“An Adventure That Went Wrong”: Reasons Given by Convicted Perpetrators of Multiple Perpetrator Sexual Offending for Their Involvement in the Offense
''An Adventure That Went Wrong'': Reasons Given by Convicted Perpetrators of Multiple Perpetrator Sexual Offending for Their Involvement in the Offense
Jessica Woodhams 0 1 2
Leigh Harkins 0 1 2
0 Faculty of Social Science and Humanities, University of Ontario Institute of Technology , Oshawa, ON L1H 7K4 , Canada
1 School of Psychology, University of Birmingham , Birmingham B15 2TT , UK
2 Teresa da Silva
There is little empirical research examining the reasons behind multiple perpetrator sexual offending. A limited number of studies provide reasons for offending offered by perpetrators of this type of sexual violence, but only one published study exists where these perpetrators were interviewed regarding their offense. The Multi-Factorial Model of Multiple Perpetrator Sexual Offending (MPSO) proposed that various factors (individual, sociocultural, and situational) play a role in this type of sexual assault, noting in particular the importance of group dynamics and processes. In the current study, 25 convicted perpetrators of multiple perpetrator sexual offending housed in educational centers and prisons in Portugal were interviewed about their involvement and reasons for participating in the offense. The findings suggested that group processes and dynamics play an important part in this type of sexual offending. Furthermore, the results provided some evidence to support the factors proposed by the Multi-Factorial Model of MPSO. These findings have implications for prevention and treatment programs and for the assessment of offenders.
Multiple perpetrator rape; Multiple perpetrator sexual offending; Group rape; Group sex offending; Sex offenders
School of Psychological, Social and Behavioural Sciences,
University of Coventry, Coventry CV1 5FB, UK
Multiple perpetrator sexual offending (MPSO)1 is an
international phenomenon that has been present throughout history and
which manifests in various settings, including street gangs,
college fraternities, sports teams, in prison, and during war and civil
(da Silva, Harkins, & Woodhams, 2013)
. In the U.S., it is
estimated that between 10 and 33% of sexual assaults are
committed by multiple perpetrators (Franklin, 2004). Similar
figures have been reported in countries such as South Africa
Jewkes, Sikweyiya, Morrell, & Dunkle, 2009)
Australian Bureau of Statistics, 2004)
, and the UK
Curran & Millie, 2003; Kelly, Lovett, & Regan, 2005; Wright
& West, 1981)
The majority of research conducted on MPSO has utilized
archival data, such as police reports and victim statements
1971; Chambers, Horvath, & Kelly, 2010; da Silva, Woodhams,
& Harkins, 2014; Horvath & Kelly, 2009; Woodhams, 2008;
Wright & West, 1981)
, court files
(Bijleveld & Hendriks, 2003;
Bijleveld, Weerman, Looije, & Hendriks, 2007)
, and law reports
(Hauffe & Porter, 2009; Porter & Alison 2006)
. These studies
have been useful in providing information regarding the
characteristics of offenders, victims, and offenses. They do not
provide information about the reasons and reported explanations
for the assault, however, which are important when trying to
1 The term multiple perpetrator rape was suggested by Horvath and
Kelly (2009) as an overarching term for any sexual assault committed by
two or more perpetrators and includes a broad range of sexual offenses. In
this article, the term MPSO is used because it is the term utilized in the
main theory examined.
intervene therapeutically with the offenders. This information
can be obtained from the perpetrators of MPSO directly although
this methodology has rarely been adopted by researchers. This
paper presents the findings of a study in which perpetrators of
MPSO were interviewed to explore their role in the MPSO and
the reasons and explanations offered for their involvement.
The findings are compared to the factors proposed in
and Dixon’s (2010)
Multi-Factorial Model of MPSO.
Theories of Sexual Offending and MPSO
Existing theories of MPSO propose a variety of contributory
factors that include individual and sociocultural factors, and
(Amir, 1971; Brownmiller, 1975; Groth &
Birnbaum, 1979; Harkins & Dixon, 2010, 2013; Sanday, 2007)
The most recent and comprehensive theory, which draws
together the factors proposed by earlier theories, is the Multi-Factorial
Model of MPSO developed by Harkins and Dixon (2010, 2013).2
This model proposes that various factors (individual,
the occurrence of MPSO
(Harkins & Dixon, 2010, 2013)
Individual factors that contribute to MPSO include personality traits (e.g.,
leadership), developmental factors, and paraphilic sexual
interests. Sociocultural factors, such as cultural norms, myths, beliefs,
and values about women, sexuality, and violence are also thought
to play a role. In particular, rape culture, rape myths,
patriarchy, and negative or stereotypical attitudes and beliefs about
women are conducive to MPSO. Situational factors are proposed
to facilitate the occurrence of MPSO by helping overcome any
inhibiting factors, or by acting as a trigger. This would include
specific contexts, such as fraternities and wars, where
exaggerated sexuality is common or hostile masculinity is acceptable.
The model explains that individual, sociocultural, and
situational factors interact in diverse ways further contributing to the
likelihood of a MPSO occurring
(Harkins & Dixon, 2013)
possible interactions are: internalization of sociocultural factors
(between the individual and the sociocultural context); group
processes (between the individual and situational factors), and
subcultural context (the situational context and sociocultural
factors). Harkins and Dixon (2013) suggested that the
internalization of sociocultural factors is associated with the degree
to which a person internalizes sociocultural norms and how
these influence their beliefs and cognitions. They emphasized
the importance of group processes in the perpetration of MPSO,
including social comparison, social dominance, conformity,
obedience to authority, social corroboration, deindividuation,
and groupthink. Lastly, the interaction between specific situational
contexts and broader sociocultural factors produces the
subcul2 For a more in depth description of this model and other earlier
explanatory theories of MPSO, see da Silva, Woodhams, and Harkins (2015) and
Harkins and Dixon (2010, 2013).
tural context. This means that given a particular type of situation,
certain cultural practices could lead men to commit a sexual
offense as a group.
There are also numerous theories of general sexual offending
which range from single- to multifactor models
Polascheck, & Beech, 2006)
that could help explain MPSO. Of these,
the most comprehensive theory that attempts to incorporate
previous theories of sexual offending is the Integrated Theory
of Sexual Offending (ITSO)
(Ward & Beech, 2006)
. This theory
proposes that sexual abuse occurs because of the interaction of
several causal factors. These include biological factors
(influenced by genetic inheritance and brain development),
ecological niche factors (social and cultural environment, personal
circumstances, and physical environment), and
neuropsychological factors (e.g., motivation/emotion, perception and
memory, and action selection and control). The ITSO includes all of
the factors proposed by the Multi-Factorial Model of MPSO
(individual, sociocultural, and situational) and effectively
explains individual sexual offending; however, it does not
specifically include the group processes that are argued to be so
important in explaining MPSO.
In contrast with the sexual offending literature, the group’s
influence is given explicit consideration in theories of general
co-offending. Within the literature on co-offending, it is
possible to identify three basic perspectives
group influence, social selection, and the instrumental
perspective. The group influence perspective proposes that
cooffending is explained by group processes (e.g., social
learning, acquisition of delinquent definitions, and group pressure)
which lead to social rewards
(Akers, 1973; Matza, 1964)
the other hand, the social selection perspective argues that
criminal groups form because offenders that share similar
characteristics select each other
(Hirschi, 1969; Kornhauser,
. According to the instrumental perspective,
co-offending is the result of a decision making process where the offenders
weigh the advantages and disadvantages of lone versus
co-offending and select co-offending because it is easier, less risky,
and/or more profitable
(Letkemann, 1973; Walsh, 1986)
Theories of general co-offending have been criticized for
, and there have been
calls for more empirical research to assess their relevance
(McGloin & Nguyen, 2012)
. In terms of their value in explaining
MPSO, they are not as comprehensive as the ITSO
or the Multi-Factorial Model of MPSO (Harkins &
Dixon, 2010) as they neglect to consider individual factors.
Past Studies with Perpetrators of MPSO
Only a limited number of studies have asked perpetrators of
MPSO about their reasons for participating in the offense, and
these questions were not the main focus of the research studies
(Etgar & Ganot-Prager, 2009; Hooing, Jonker, & van Berlo,
2010; Jewkes et al., 2006; Jewkes, Sikweyiya, Morrell, & Dunkle,
2011; Scully & Marolla, 1985)
Etgar and Ganot-Prager (2009)
examined the advantages of including adolescents who
participated together in the same MPSO in the same therapeutic
group and reported what the adolescents said in group therapy
about their involvement in the assault. The young offenders
often reported a need for social acceptance or feelings of social
pressure as reasons for their involvement in MPSO. Illustrative
quotes included statements about wanting to belong and become
one of the group, and fears of rejection if they did not participate.
The characteristics of juvenile sex offenders (including
perpetrators of MPSO, n = 142) in a mandatory sex education
program were analyzed by
Hooing et al. (2010)
. Explanations for
and feelings about the crime that were described by the young
offenders at the beginning of the program were examined.
Multiple perpetrator sexual offenders had more negative attitudes
toward girls compared with lone sex offenders who had assaulted
a peer. Additionally, 50% (n = 72) of the multiple perpetrator
sexual offenders stated that an important motive for offending
was group pressure or group dynamics. For these offenders,
nonsexual reasons for participating in this type of offense, such as
those related to sociability and social dominance, were more
prevalent than sexual motives, such as sexual arousal. In fact, only 13%
(n = 18) stated that sexual arousal was a reason for the offense.
In South Africa, survey studies were conducted with men
from the community (n = 1686) where, among other questions
related to health issues, male adolescents and adults were asked
about the perpetration of rape, including MPSO
(Jewkes et al.,
. Among these men, 9% (n = 149) had committed a
multiple perpetrator sexual offense. The reasons that were given
by the men for their involvement in MPSO included: sexual
entitlement, boredom, fun, alcohol consumption, peer pressure,
and a desire (motivated by anger) to punish girls or women who
did not conform to stereotypical gender norms (e.g., the women
and girls were considered promiscuous, or drank alcohol and
smoked, or were lesbians).
Scully and Marolla (1985)
interviewed convicted rapists
(n = 114), including multiple perpetrator rapists, and asked a
number of open-ended questions on the offenders’ own
perceptions of their crimes. The most common reasons given by
multiple perpetrator rapists for participating in an assault
were related to recreation and adventure. Male camaraderie
was also highlighted as important, which was achieved by
participating together in a dangerous and illicit activity.
The only published study that focused exclusively on
interviews carried out with perpetrators of MPSO was conducted by
. In order to further understand the group
process in MPSO, Blanchard interviewed seven teenage boys who
had been involved in one of two different multiple perpetrator
sexual offenses (three belonged to one group and four to the other
group). At that time, psychologists based their explanations for
this type of sexual violence on psychodynamic theory (which
considered the relevance of homosexual factors in MPSO).
Blanchard carried out psychological tests, including the
Rorschach, which were administered individually and then to
the group. Blanchard claimed that some of the results
suggested the existence of homosexual factors: The sexual feelings
identified in one of the rapes were to a great extent between
the perpetrators instead of between any of the perpetrators and
the victim. In the final conclusions, Blanchard identified a
clear leader in both of the cases and stated that they were
sexually stimulated by the presence of the group. However, he
thought that in one of the cases, the sexual feelings that were
stimulated did not appear to be homosexual. Instead, the leader
was thought to be defending himself against the fear of being
weak or not masculine enough. Blanchard highlighted the
importance of the leader and argued that a central factor in a
group rape is the degree to which the leader is able to direct the
attention of the other members of the group to sexual issues.
Additionally, he noted that the group dynamics operating
between the leaders and the rest of the group members during
the group evaluations were similar to the dynamics present
during the actual assault.
In conclusion, most of these studies reported that many of
the reasons given by participants for taking part in MPSO were
non-sexual. Furthermore, they suggest that group processes and
dynamics play an important role in MPSO.
One of the most effective ways of gathering information
regarding reasons for offending and the role of group dynamics
is from the perpetrators of MPSO themselves. As noted above,
very few studies have adopted this approach and the main focus
of those studies was not the offenders’ account of their reasons
for participating in the offense. There is only one published study
where the focus was exclusively on
interviewing perpetrators of MPSO. However, this study had a very
limited sample size (of teenagers only), is more than 50 years old,
and focused mainly on examining if there were homosexual
factors present in MPSO.
In an effort to address this gap in the MPSO research, the
authors of the current study sought to interview convicted
perpetrators of MPSO about their involvement, experiences
and reasons for participating in the offense. The current study
addressed the following research question: What reasons do
convicted perpetrators of MPSO give for their involvement in
the offense? It is important to address this research question
because it is pertinent for prevention, assessment, and
treatment purposes. For example, if empirical studies are able to
demonstrate that group processes are a central part of this type
of sexual offending (as is proposed by theories of MPSO), then
these would be a clear target for prevention and treatment efforts,
and are relevant to the assessment of offenders. Furthermore,
there may be other factors unique to MPSO that need to be
identified and taken into account. Since this is a qualitative
study, formal hypotheses were not formulated a priori to avoid
any potential bias in interpreting the results. However, based
on the literature reviewed, it was expected that at least some of
the offenders would cite group processes as related to their
involvement in MPSO.
A total of 25 offenders convicted of MPSO agreed to
participate in the study, which is noted as an acceptable size for a
qualitative study employing thematic analysis
& Johnson, 2006)
. As can be seen in Table 1, the offenders ranged
in age from 13 to 45 years (M = 19.3, SD = 8.5), although the
majority (72.0%, n = 18) were juveniles aged from 13 to 17 years.
Approximately half (52.0%, n = 13) were of African ethnicity,
followed by White (36.0%, n = 9), Romany (8.0%, n = 2), and
Mixed Race (4.0%, n = 1). In terms of education, their years of
schooling ranged from 0 to 8 years (M = 5.4, SD = 1.6). More
than half (56.5%, n = 13) were living with parent/s or were
students (54.2%, n = 13) at the time of the offense.
Offense and Victims
The interviews related to 21 different offenses. As can be seen
in Table 2, for four of these offenses, two different offenders
who had participated in the same offense were interviewed.
The number of offenders present in the offenses ranged from 2
to 8 (M = 3.5, SD = 1.7). In 16 cases (76.2%) the victims were
female; the remaining five (23.8%) were male. In
approximately two-thirds of the offenses (61.9%, n = 13) the victims
were known to at least one of the offenders. The majority of
the offenses occurred while the offenders were socializing
(66.7%, n = 14). In four cases (19.1%) they occurred during a
robbery. In cases involving couples, the victim was moved to
a different location from their partner for the offense. The
remaining three cases (14.3%) involved male school-age victims and two
occurred at school in changing rooms. The last one occurred
outside of school and the offenders claimed that their intention was to
punish the victim.
A research proposal was sent to the Portuguese Parole and Prison
Services (Direc¸a˜o-Geral de Reinserc¸a˜o e Servic¸os Prisionais—
DGRSP) requesting to interview offenders convicted of MPSO
and access to their case files. The files included detailed court
accounts of their offenses and the facts that were proved in court.
The case files were read by the first author before the interview
and the offenders were informed of this. The research proposal
was granted full ethical approval by the Science, Technology,
Engineering and Mathematics Ethical Review Committee at the
University of Birmingham, UK. It was also approved by the
DGRSP. The first author, who is fluent in Portuguese, was
permitted access to five Educational Centers (where young
offenders under the age of 16 are held) and four prisons (with
offenders from age 16 upward). Offenders convicted of MPSO
were approached individually by the first author who provided
information about the study, including an information sheet.
The offenders who agreed to participate signed a consent form.
The interviews were semi-structured using an interview
schedule that consisted of open-ended questions related to what
happened before, during, and after the offense and with prompts
to elicit more detailed responses (e.g., Could you explain how
the offense occurred? Could you explain what happened during
the assault? What was your role? How did the offense end?). It
should be noted that the interview schedule was not structured
around assessing factors from any particular theories, such as the
Multi-Factorial Model of MPSO
(Harkins & Dixon, 2010)
interviews of 14 participants were audio-recorded with their
permission. However, 11 participants did not want their
interviews to be audio-recorded and instead, hand-written notes were
made by the interviewer. Shorthand was used which facilitated
the note taking and only the quotes that were verbatim are included
in the paper. The interviews were conducted individually in a quiet
room or office in the educational centers and prisons where
privacy was guaranteed. They lasted between 20 min and 1 h. The
shorter interviews were those conducted with the very young
offenders (13–15 years) who struggled to talk about their
reasons for being involved in the offense. The audio-recorded
interviews were transcribed verbatim by the first author and then
translated into English. The majority of the participants’ language
skills were poor, and Portuguese was not the first language of
some of the African participants. When translating the verbatim
transcripts, the first author did not correct the poorly constructed
sentences or the grammatical errors as the authors considered that
it was important to have a true translation of the transcripts. The
recordings were deleted after the transcripts were made. Any
identifying information was omitted from both the transcripts
and the hand-written interviews.
The study design was qualitative, and thematic analysis was
used to analyze the interviews. The guidelines for conducting
thematic analysis recommended by
Braun and Clarke (2006
Guest, MacQueen, and Namey (2012
) were followed.
An inductive ‘‘bottom up’’ analysis was conducted which was
. The first author familiarized herself
with the data while transcribing and translating the interviews.
The translated transcripts were imported into NVivo10, a
computer software package that facilitates the organization and
analysis of qualitative data. The whole data set was read and
reread, and first ideas were noted. Next, initial coding was
conducted in a systematic form across the entire data set. This was
achieved by identifying interesting features of the data that were
linked to corresponding codes or sub-codes. As new features
were identified, additional codes were generated. When
reoccurring aspects of the data were identified, these were linked to
existing codes in the coding scheme. After all the data were coded,
these codes and sub-codes were sorted and collated into potential
themes. Thematic maps were employed to facilitate the sorting of
codes and sub-codes into themes as they enabled the visualization
of relationships. The initial themes were then reviewed and
refined at the level of the coded extracts and in relation to the
whole data set. Lastly each theme was further refined, defined and
named. An iterative approach was utilized throughout the analysis
where codes, sub-codes, themes and sub-themes were constantly
re-examined, and revised when appropriate. For the purpose of
this article, only the themes related to the research question of this
study are presented (i.e., what reasons do convicted perpetrators
of MPSO give for their involvement in the offense?).
Six themes were identified that related to reasons given by the
participants for being involved in a MPSO: (1) started as
something else, (2) influence of others (direct or indirect), (3) lack of
insight, (4) victim blaming, (5) influence of alcohol and or drugs,
and (6) normalized sexual violence (see Table 3). In most cases,
not just one reason was given and it was common for the
participants to consider various factors as having played a role in the
offense. The interviews were compared to the court accounts in
the offenders’ case files and it was found that the majority were
similar to the court accounts, although some minimization was evi
dent in several interviews.
Started as Something Else
Most of the participants denied that they had planned to
sexually assault the victims beforehand. Only two (8.0%) of the 25
participants admitted that the group had planned earlier to have
sex with the victim. The rest of them (n = 23, 92.0%) stated that
the offense had started out as something else, such as a game or
joke, physical bullying, or a robbery:
changed when the victim said that she was only willing to have
sex with one of them.
P10: I was having a swimming lesson with those two
colleagues and that started off as a joke (pause) and (pause)
and I had no intentions of rape or anything. At that time, I
(pause) didn’t know the consequences it could bring and
(pause) so we started joking around and all of that but
not (pause) not, it wasn’t intentional.
P8: We didn’t plan the sexual thing but we planned to
beat him because he had made a complaint.
P20: Yeah, we left, left with the purpose of (pause) of going
to rob and and (pause) we went (pause) to (pause) and when
I realized what was happening (pause) pfff (pause) it had
already happened, I don’t know.
Even in one of the cases where the participant admitted that
they had planned among themselves to have sex with the
victim, he stated that they had not discussed using force as they
thought that she would be willing. He described a situation that
started off as having fun with his friends and expecting that the
victim would want to have sex with all of them because she was
known to have participated in similar situations in the past. It all
P9…The three of us were already expecting that there
was going to be sex between the four of us, no there were
five, one walked away. We were already expecting but
we weren’t also expecting that she wouldn’t, wouldn’t
P9: …I didn’t intend to want to force, to want to force
her. So this for me, I considered this an adventure that
The participants were not able to clearly explain why the
situation escalated into a sexual assault. A few pointed to factors
related to loss of control, adrenaline, and an impulse, but as can
be seen in the quotes below they also considered other factors
such as influence of others or being drunk. It is possible that a
combination of factors was present and played a role in the
P8: We didn’t control ourselves (pause) I don’t know.
P19: …I don’t know how to explain why I did it, if it was
adrenaline or if I let myself be led.
This table shows how the themes identified in the current study map on to the factors proposed by Harkins and Dixon’s (2010, 2013) Multi-factorial
Not surprisingly, since MPSO is an offense carried out in the
presence of other people almost half (n = 12, 48.0%) of the
participants spoke about the influence of others. This influence
was either direct, where the participants had been ordered, told,
or invited to participate in the offense by a co-offender, or
indirect, where they were not directly ordered to participate but did so
because the others were present or actively involved. Directly
telling or ordering a co-offender to participate was only evident in
a few cases. In some of these cases it took the form of a direct order
(the quotes below correspond to what was in the court accounts in
the offenders’ case files):
P7: It was at that time, one of them ordered (pause) he
turned to the victim and ordered him to turn around (pause)
Interviewer: Yes and then?
P7: I was ordered to go first.
P15: I ordered him. I said like this:‘‘Do that to him’’(pause)
and he did it.
In other cases, it occurred not as a direct order but at the
insistence of a co-offender that he should take part in the offense:
P21: So I got there, the other one was doing it, that’s it, get
there be faced with that, then they start to influence: ‘‘Oh
come, come, take, go on, go on’’and in that situation, it isn’t,
it isn’t, I don’t know, it is things that (pause) the influence is
such that you are so into that situation that you go.
This insistence also included taunting and making the
cooffender look bad if he did not participate:
P18: We were all drunk and he then didn’t give up, he
pushed me, pressured me ‘‘If you don’t go, you are a
coward’’and I ended up by accepting his invitation.
Combination of individual, sociocultural, and situational factors
Group processes (social comparison and conformity)
Group processes (deindividuation)
When participants referred to the indirect influence of others,
they stated that the co-offenders had not told them to participate,
but that they chose to do so themselves. This happened in some
cases simply because they were seeing the others participate and
either felt aroused or decided that they also wanted to be involved:
Interviewer: Was there someone who said to do that?
P3: No, I think it was because a person seeing someone
having relations also becomes motivated.
Not wanting to look bad in front of the co-offenders and
participating to avoid being rejected was also mentioned:
P9: Because I was, I was with (pause) how shall I explain
(pause) because I didn’t (pause) want to appear weak, I
didn’t want (pause) to, to have hassles. Not to be rejected
by them. It was more for that and since I was there in the
middle (pause) I also tried to go.
Lack of Insight
Almost one quarter (n = 6, 24.0%) of participants described a
lack of insight into their thoughts and feelings at the time that
they participated in the offense. They had difficulty describing
the assault or parts of the assault. This difficulty did not seem to
be just related to the fact that it is a sensitive and difficult topic
to talk about; they described the offense as being confusing or
happening very quickly:
P13: I don’t know how to explain very well (pause)
hmmm (pause) it was all confusing (pause) it was all a
bit confusing (pause) hmmm.
P20: I don’t know (pause) pfff (pause) man that (pause)
I don’t know really that was kind of (pause) pfff (pause)
something very fast really (pause).
Furthermore, they were unable to explain why they took part
in the assault or what might have influenced their behavior at the
P22:…even now I ask myself, what came over me I don’t
know, I don’t know what came over me, a thing (pause)
man a person doesn’t have an explanation.
P20:… I don’t know what crossed through my mind to
do a thing like that, until today I also can’t think.
As in lone sexual offending, it was also found that almost half
(n = 12; 48.0%) of the offenders blamed the victim for the
offense. This was done to differing degrees, which ranged from
attributing all the blame to the victim to insinuating that the victim
held some responsibility. A few participants directly stated that it
was the victim’s fault because she/he had wanted to participate or
came up with the idea:
P1: No, my crime was because she wanted to. She said
that she would do that if we let her into the group, and
my colleague said ‘‘Oh yes? Come on then’’
Other participants did not attribute all the blame to the victim,
but they did suggest that the victim had wanted to participate and
then changed her/his mind later on:
P6: …but that guy that did this, he also did it because he
wanted to. He then afterwards (pause) we started, started
talking and making fun. So he did something like that and
then went to complain to the police.
Additionally, the victim’s behavior at the time of the offense
was also seen by some of the participants as contributing to the
offense. One of the participants recalled how the victim had said
that she only wanted to have sex with one of the members of the
group but that she talked about her feelings for the other
members of the group and that this led to some confusion:
P9: And also the conversation she was having because
she just wanted to have with one, but then she would
also say‘‘Oh I like you a little bit, I used to like you more,
I like him a little bit’’and I don’t know what. We all stayed
with that thing in our head. In the end she just wanted to
have it with that one, with that one. It was (pause) it was a
Finally, some participants spoke about the victim’s past
behavior and her/his reputation of having had sexual relations
with various people or having participated in group sex in the
past. In one case the participant insinuated that this showed
that the victim did not have credibility:
P4: I also have (pause) have witnesses from the people
who helped me because they knew how she was. She would
go with everybody (pause) from the school.
In other cases the participants suggested that it led them to
believe that the victim would be a willing participant:
P9: But us, between ourselves (pause) because of the
history that she already had (pause) of, of having relations
This was also the case with one of the male victims who was
a vulnerable young adult with a learning disability who had been
taken advantage of in the past by other people:
P6: That guy there (pause) we did this, but I know people
that also had (pause) or paid or something like that or they
would buy him something.
Influence of Alcohol and/or Drugs
Overall, almost one quarter (n = 6, 24.0%) of the participants
mentioned the influence of alcohol and/or drugs. More than half
(n = 4, 57.0%) of the adult participants stated that one of the
main reasons that they participated in the assault was because
they were either drunk or under the influence of drugs. This was
a reason very rarely given by the juvenile participants and only
two (11.0%) young participants (one who committed the offense
with two adult co-offenders) said that it was a reason for being
involved in the offense:
P6: I was at a party and so me and my friends had already
drank a bit and then we got into some drugs and it was there
that caused (pause) nothing else.
In some cases, the juvenile participants admitted to having
drunk alcohol or smoked drugs but stated that it had not played
a role in the offense:
P13: No, I don’t think so (pause) yes we had drunk (pause)
but I think wine, but it was with 7Up (a fizzy drink), but
many hours had passed since that happened.
P14: No, that happened not because because I smoked
hash, which I always smoked since a child.
The adult participants who considered that alcohol had
contributed to them being involved in the offense saw it as
influencing their behavior and decisions:
P23: It was bad influence of the alcohol.
One of the participants was able to describe in more detail
how that influence occurred and believed that it made him
more susceptible to the influence of others:
P18: Then also with alcohol, I become, I become weak
(pause) thinking is weaker. Oh so I go to show that I’m
not a coward. That’s it, with drink with alcohol that is
what I become. ‘‘You are a coward you won’t do this’’.
‘‘Oh yeah, I won’t do it? Do you think that I won’t do it?
Now I’m going to do it so that you can see’’.
P18: And (pause) if it wasn’t for, if I wasn’t drunk I could
have not gone because me with behavior of, with alcohol
I’m one person, without alcohol another. With alcohol I
don’t care about many things, without alcohol, but when
I’m with alcohol I’m a person that goes. They pull me by
the hand, say‘‘Come,’’say‘‘Let us go walk for a while’’I
go. I’m like that decide (pause) decide easily.
Normalized Sexual Violence
In a few of the juvenile cases, the participants referred to not
being aware of the seriousness and consequences of their acts
and a couple (8.0%) of participants mentioned how they had
already witnessed similar situations in the past and that is why
they did not think that it was serious. It is important to note that
these participants came from poor, crime-prone neighborhoods
where gang culture was common. One participant spoke quite
extensively about how he had seen consensual group sex and
multiple perpetrator rape occurring, and therefore, he thought
that it was something normal:
P14: I got dressed and (pause) and then her friend appeared
and said‘‘Oh you brought her here for this! I thought it was
to talk’’. And I said ‘‘Oh you look like you don’t know,
don’t know this (pause) this type of routine’’. Routine but
I say routine because (pause) I had already heard and seen
some of these things, this type of thing and she knows, it
had already happened to her but (pause) it was because
she wanted to, not because she was forced, yes.
P14: No (pause) because I had already seen (pause) many
episodes of those and (pause) and nothing happened and I
said this isn’t more than something normal as well, as if I
was stealing a mobile phone and that (pause) yes yeah.
P14: Sometimes they wanted to…they agreed and there
were other days that I saw that they didn’t agree. I don’t
want to say that it was always the same people, no, it was
like normal, like I knew…yeah normal.
Another participant also spoke about situations of group
sex that he had witnessed and stated that there was even a
name for the type of girl that takes part in this activity:
P3: Don’t you know? (pause) Haven’t you ever heard
that word ‘‘ger’’?
Interviewer: What? P3: ‘‘Ger’’
P3: It is a girl that goes to someone do you see? And the
friend takes someone else and then both of them have
relations with the girl do you understand?
Interviewer: So is it that frequent? P3: Exactly but it is with consent because the girl lets.
This study examined the reasons that convicted perpetrators of
MPSO gave for their involvement in an offense. Six main themes
were identified which included: started as something else,
influence of others (direct or indirect), lack of insight, victim blaming,
influence of alcohol and/or drugs, and normalized sexual
violence. However, in most cases the participants did not report just
one main reason for being involved and usually described a
combination of various factors and reasons. The results,
therefore, support the existence of some of the factors proposed by the
Multi-Factorial Model of MPSO
(Harkins & Dixon, 2010, 2013)
and earlier theories (see Table 3). The findings will be examined
in more depth and discussed in the context of prior research in the
area of general and sexual offending.
The theme started as something else (i.e., participants
explained how they had not planned a sexual assault but that
somehow it had happened) indicates that it is probable that a
combination of individual, sociocultural and situational
factors led to the assault. For example, in the situations where the
participants said they were just having fun together, there may
have been an interaction between individual traits (which could
be related to personality, developmental factors, or sexual
interests), beliefs about stereotypical masculinity, and a situation
where co-offenders are present and are drunk, excited and/or
aroused, as well as an available victim.
Research findings show that in the majority of group crimes
there is little planning, and many occur, in part, due to impulsive
Alarid, Burton, and Hochstetler (2009
found that street robbery committed by multiple perpetrators is
often a spontaneous, impulsive opportunity that did not involve
any planning. Furthermore,
suggested that young
people can engage in criminal behavior without fully meaning
to do so. Processes, such as behavioral contagion, can contribute
to this unintended outcome
(Polinsky, Lippitt, & Redl, 1950)
stated that behavioral contagion occurred when
an individual performs an action and, as a result, another
individual (who was uncertain whether or not to perform this action)
acts in the same way. Contagion involves a circular process where
members of a group do not examine the meaning of another
. This is facilitated by other
processes such as deindividuation, which is discussed below.
Two individual characteristics in this sample which seem to
be pertinent to this theme are the age and ethnicity of the offenders.
The majority of the offenders were under 18 years old which is
consistent with what is found in the MPSO literature
1979; da Silva et al., 2014; Hauffe & Porter, 2009; Horvath &
Kelly, 2009; Porter & Alison, 2006; Wright & West, 1981)
Additionally, in the co-offending literature, young age has also been
associated to co-offending
. Furthermore, it seems
that there may be some differences between the young and the
adult offenders as the adult offenders stated more frequently
that alcohol played a part in their offense and that their
co-offenders had a direct influence on their behavior.
noted that in the literature on lone sexual offending, it has
already been established that there are clear differences between
adolescent and adult sexual offenders and that these should also
be considered in order to tailor therapeutic interventions when
working with perpetrators of MPSO. Etgar highlighted that
these differences are apparent in emotions, cognitions, attitudes,
and behaviors due to the fact that adolescents experience the
world in a different way to adults. Furthermore, it is thought that
adolescents’ sexually harmful behavior is rarely related to
sexual deviance and is more often linked to their lack of perception
regarding the harmful effects of their behavior
More than half of the offenders were from ethnic minority
groups, which is also consistent with previous literature
Vogt, Plattner, Steinhausen, & Bessler, 2012; Bijleveld &
Hendriks, 2003; da Silva et al., 2014; De Wree, 2004; Horvath &
Kelly, 2009; Woodhams, 2008)
. Past studies have shown that,
especially in young incarcerated populations, ethnic minorities
are over-represented (Bauer et al., 2011). Additionally, several
risk factors for criminal behavior have been identified in ethnic
minority groups which include discrimination in the host
society, difficulties in acculturation and integration, and the
socioeconomic gap between ethnic minorities and nationals
et al., 2011; Mirsky, 2012)
Young age and ethnicity of offenders are not considered to
be causal factors of MPSO, but these characteristics could be
viewed as risk factors that, in association with other factors
(e.g., sociocultural and situational), could increase the
likelihood of engaging in this type of offending.
Clear evidence is provided for the existence of group
processes and dynamics in some of the reasons given by the
participants for being involved in MPSO. It is possible to identify
group processes proposed by
Harkins and Dixon (2013)
as social conformity and social comparison, in the theme related
to the influence of others. Social comparison theory is related to
an individual’s needs for affection and inclusion, whereby an
individual may reluctantly go along with a sexual assault in an
attempt to try to meet these needs
(Harkins & Dixon, 2013)
Social conformity reflects an individual striving to be
consistent with the group norms by altering his beliefs, statements, or
behaviors (Baron & Kerr, 2003). This conformity is influenced
by rewards and punishments controlled by the group.
and Dixon (2013)
considered that some individuals would
participate in MPSO to avoid being rejected or even punished by the
group and losing rewards they received from the group. When the
participants of the current study spoke about the influence of
others, some of them directly stated that they did not want to look
bad, to have problems with the group, or be rejected by their
peers, which clearly points to the presence of social comparison
and conformity. Others did not report these reasons directly, but
disclosed obeying an order without questioning it, and others
stated that they participated after the co-offenders either insisted
they do or taunted them. This is suggestive of either being scared
of the other co-offenders and not wanting to be punished by them,
or wanting to belong to the group and therefore acting in a way
that would demonstrate that they were part of it. These findings
are consistent with previous studies which reported that the
reasons that perpetrators of MPSO gave for participating in the
assault were related to social comparison and conformity
& Ganot-Prager, 2009; Hooing et al., 2010)
Modeling is another group process that is relevant to the theme
of others. O’Sullivan (1991
) considered that this group
process was relevant to MPSO because by watching peers
sexually assault a victim, not only do the members of the group learn
that it is acceptable, but also how to do it. In the current study,
some participants reported how they took part after seeing their
co-offenders assault the victim.
In the theme related to lack of insight, participants described
not having insight into their feelings and thoughts and that the
events happened quickly and in a confusing manner. This could
indicate the influence of the group process deindividuation.
Deindividuation is where a person loses his/her sense of
individuality, becoming less self-conscious, and is submerged into
) believed that
deindividuation could be responsible for a state of reduced
selfawareness, including a reduced awareness of personal beliefs,
attitudes, and standards. In the current study, some participants
stated that they could not understand how they had assaulted
the victim; that it was something that they had never thought
Harkins and Dixon (2013)
considered that in
MPSO, deindividuation could help to explain how a person can
lose his/her sense of identity and responsibility and go along with
In the theme victim blaming, sociocultural factors related to
beliefs and attitudes about women, sexuality, rape myths, and
gender norms were implicated. Some participants in the study
spoke about how the female victim was judged by her past
behavior. If she had, or was believed to have had, many sexual
partners in the past, or to have participated in group sex, she was
seen as someone who would be willing to have‘‘sex’’with all the
group members. This was also apparent in a case with a male
victim, who was a vulnerable young adult.
There were some distinct aspects to the cases involving male
victims. In the majority of cases they were younger and
physically weaker than the perpetrators. In three cases, they were
school colleagues of the offenders and the offenses seem to have
occurred in a bullying context. In one of the cases, the offenders
admitted that their aim was to punish the victim because he had
complained to the school when they had previously bullied him.
In the only case in which the victim was an adult male, he had a
learning disability and had in the past been abused by other
people. A few authors have proposed that men targeted for MPSO
are perceived by the perpetrators as not fitting into stereotypical
gender normsbecause, forexample, theyareconsideredphysically
or mentally weak, or homosexual
(Franklin, 2004; Lees, 2002)
Sociocultural factors can also be identified in the theme
normalized sexual violence. More specifically, in this theme,
sociocultural factors seem to be interacting with situational
Harkins and Dixon (2013)
described this interaction as
‘‘subcultural context.’’A couple of participants who came from
crime-prone neighborhoods known for their gang culture
explained how they considered what they had done to be normal
because it was something that they had already witnessed and
was acceptable in their circle of friends and acquaintances. This
demonstrates how broader sociocultural factors (attitudes toward
women and sexuality) can interact with situational factors (crime
and gang culture) and increase the likelihood of MPSO.
Situational factors can be identified in the theme influence of
alcohol and/or drugs. The participants that spoke about this
theme considered that they would not have committed the assault
if they were not under the influence of alcohol. They considered
that the alcohol had a disinhibiting effect or had clouded their
judgment. Nevertheless, they did not see it as the only factor and,
in one of the quotes above, a participant explained how alcohol
allowed him to become more susceptible to the influence of
others. He felt that he had assaulted the victim not only because
he was drunk, but because, by being drunk, he was more
susceptible to the coercion and taunts of his co-offender. Studies
have frequently found that in approximately half of sexual
assaults, the perpetrator had been drinking alcohol
Zawacki, Buck, Clinton, & McAuslan, 2004)
consumption can have a number of pharmacological and
psychological effects on an individual
. It can hinder
cognitive functions, such as reasoning, memory, and judgement,
and impede response inhibition
(Abroms, Fillimore, &
. The alcohol myopia theory
(Steele & Josephs,
proposes that, when under the influence of alcohol, people
tend to focus on the most immediate and salient cues. Therefore,
they would not have the capacity to take in cues such as risks or
future outcomes. There may also be an expectancy effect
& Messerschmidt, 1993)
, whereby if a person believes that they
will behave in a certain way when they drink alcohol, then they
will behave in that way. It has been found that men expect to
feel more aggressive and sexually aroused after drinking alcohol
(Tuliao & McChargue, 2014)
. This is linked to the deviance
(Miller, Maguin, & Downs, 1997)
suggests that some people use alcohol as an excuse for
premeditated behaviors and then blame those behaviors on alcohol.
While self-reports from offenders make it possible to obtain their
own accounts and opinions about their involvement in their
offenses, they do have limitations. For example, some offenders
may try to minimize or even deny their involvement in the
offenses in order to present themselves in a more favorable light,
which can affect the reliability of these accounts. Offenders often
use minimizations and post hoc excuses when talking about their
offenses. This is not surprising since, outside the criminal context,
post hoc rationalizations and excuses are widely used by people
when they do something that is perceived to be negative
& Mann, 2006)
. Excuse making has been described by
and Higgins (1988)
as an adaptive mechanism, which is
important in maintaining self-esteem and coping with stress and
anxiety. In addition, the post hoc explanations for their offending
provided by the offenders might not be accurate because people
can have little direct introspective access to their cognitive
Nisbett and Wilson (1977)
suggested that when people try
to explain the causes of their behavior they do so based on a priori
implicit causal theories about the extent to which a certain
stimulus is a believable cause of a given response.
In recognition of this, the offenders’ case files, which
included detailed court accounts of the offenses, were read by the
interviewer before the interviewsand the offenders were informed
In the main themes identified, there is very little reference to
individual factors. During the interviews, a few offenders did
speak about individual factors, such as going through a difficult
period at the time the offense occurred because of family
problems, or considering that at that time they were very young,
immature, or irresponsible. Nevertheless, it was not a
well-developed theme and this could be due to the fact that the focus of
the interviews was on what happened directly before, during and
after the assault, rather than specifically prompting for individual
factors. This could be considered a limitation of this study and in
future research it would be useful to explore possible individual
Another limitation of this study is that the sample consisted
exclusively of convicted offenders of MPSO. It is well known
that a significant number of sexual assaults are not reported to
(Walby & Allen, 2004)
. Furthermore, Andersson,
Mhatre, Mqotsi, and Penderis (1998) found that victims of MPSO
were less likely to report the crime to the police than victims of
lone sexual violence. This makes it difficult to generalize the
findings to unconvicted MPSO offenders, as the perpetrators’
experiences and explanations could be different. Further research
using community samples is needed to overcome this limitation.
The results of this study have implications for prevention,
assessment, and treatment purposes. Although a number of
dynamic risk factors for sexual violence in general have been
(e.g., Mann, Hanson, & Thornton, 2010)
specific to MPSO remain to be identified. For some of these offenders,
MPSO-related factors might be the only dynamic risk factors
present. The results from the current study highlight the
importance of group processes in MPSO. These should, therefore, be
identified and addressed in prevention and treatment programs.
Etgar and Ganot-Prager (2009)
have noted previously that the dynamics observed between group
members during evaluation and therapeutic intervention were
similar to those reported to be present during the sexual assault
itself. Therefore, as
suggested, it is important to
examine the perpetrator’s social role within the offending group.
This will provide more information about the offender and his/
her expected interactions in a group therapy setting, as well as
possible risk factors which need addressing through
intervention. For instance, if it is identified that an offender is susceptible
to being influenced by others, therapeutic work could focus on
increasing their self-control and assertiveness. A meta-analysis
on the effectiveness of self-control programs among children and
adolescents found that these interventions can reduce
(Piquero, Jennings & Farrington, 2009)
. It has also been
found that cognitive-behavioral treatment programs (e.g., the
‘‘Reasoning and Rehabilitation’’ program) that include
components such as social skills training, assertiveness training,
interpersonal training, and social perspective training are effective in
(Tong & Farrington, 2006)
. Similarly, with
regard to prevention programs with young people, issues such as
peer pressure and group processes should be addressed.
and Jolliffe (2012)
evaluated a number of peer influence and
mentoring programs which targeted peer relationships and
decision making within the context of peer interactions, and
found some promising results in relation to the reduction of
The findings support a multi-factorial explanation of MPSO
which means that, besides group processes, other factors are
also present and should be taken into account for prevention,
assessment, and treatment purposes. Themes consistent with
sociocultural and situational factors were identified that, in
interaction with individual factors, likely led to the offense.
Although more research is necessary to gain a better
understanding of these factors and how they interact, Harkins and
Dixon’s (2010, 2013) Multi-Factorial Model of MPSO provides
a useful framework for understanding this type of sexual violence.
As expected, group processes and dynamics were given as
reasons for their involvement in MPSO by the offenders we
interviewed. Additionally, other explanatory factors (i.e.,
sociocultural and situational) that had been proposed by Harkins and
Dixon (2010, 2013), and in earlier theories
Brownmiller, 1975; Groth & Birnbaum, 1979; Sanday 2007)
were present in the main themes identified from the interviews.
Furthermore, the participants tended to attribute their offending
to multiple factors, rather than just one. This supports the
proposition of multiple, interacting factors explaining the perpetration
of MPSO. These findings provide some evidence to support the
Multi-Factorial Model of MPSO and other theories of MPSO that
have been proposed
(Amir, 1971; Groth & Birnbaum, 1979)
Acknowledgements We thank the Portuguese Parole and Prison
Services (Direc¸a˜o-Geral de Reinserc¸a˜o e Servic¸os Prisionais—DGRSP) for
allowing the collection of data in Portuguese Prisons and Educational
Centers. The first author is funded by FCT (Fundac¸a˜o para a Cieˆncia e a
Tecnologia) through the Grant SFRH/BD/68429/2010.
Compliance with Ethical Standards
Conflict of interest The authors declare that they have no conflict of
Ethical Approval All procedures performed in studies involving human
participants were in accordance with the ethical standards of the
institutional and/or national research committee and with the 1964 Helsinki
Declaration and its later amendments or comparable ethical standards.
Informed Consent Informed consent was obtained from all individual
participants included in the study.
Open Access This article is distributed under the terms of the Creative
Commons Attribution 4.0 International License (http://creativecommons.
org/licenses/by/4.0/), which permits unrestricted use, distribution, and
reproduction in any medium, provided you give appropriate credit to the
original author(s) and the source, provide a link to the Creative
Commons license, and indicate if changes were made.
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