Reasons for NSSI

Several studies have investigated the psychological motivation for NSSI [21, 22] and their results used to support a four factor explanatory model comprised of intrapersonal negative reinforcement (e.g. reduction of negative emotions such as anxiety or anger); intrapersonal positive reinforcement (e.g. to relieve feeling numb or empty); interpersonal positive reinforcement (e.g. gaining attention or emotional support from peers); and interpersonal negative reinforcement (e.g. reduction in victimisation) [23]. Other researchers propose a simpler two factor interpersonal and intrapersonal model [21]. Irrespective of the method of assessment, NSSI performs a clear social and communicative function among teenagers which is arguably linked to their social identity. For example, a study of Emo teenagers argues that online exchanges about self-injury methods, interpersonal and intrapersonal justifications for self-injury are common, as are vivid descriptions of peer victimisation [11].

Youth identity, psychopathology and self-harm

Both sociology and psychology consider youth culture to be an important phenomenon. Within social psychology youth identity is often termed “adolescent peer crowd affiliation or identification” and is tied to social identity theory [24]. This theory is supported by experiments showing how even minimal identification with a ‘fictional’ social group leads to increased in-group influence and adoption of stereotypical in-group behaviours, particularly among newer members [25]. Western adolescents readily identify with specific ‘social crowds’ and accordingly real social groups should exert considerably greater influence than fictional ones. Common peer crowds include the Brains or Nerds (academic), Jocks (athletic), Burnouts (substance using and antisocial) and Nonconformists (rebelling via unusual clothing or ideas) with each type linked to a specific health behaviour profile. For example, Burnouts and Nonconformists engage in more risky behaviours [26] and Burnouts report poor psychological health [27]. The generic descriptions and associated risk behaviours of the Burnout and Nonconformists overlap with those of Alternative subcultures within the sociological literature.

Within sociology youth subculture is related to classic subculture and deviance theory. These explain youth subculture as a reaction to mainstream (particularly middle-class) values and as a method for marginalised youth to achieve a form of status within a social system that conflicts with their ideals. Contemporary research often focuses on (adult) Punk, Goth and related subcultures and stresses the importance of two areas; out-group distinction and in-group socialisation [28]. Out-Group Distinction relates to how in-group values, symbols and practices distinguish members from ‘mainstream’ society, while In-Group Socialisation refers to subcultural social ties, conventions, commitment and in-group status. Milner’s qualitative study of high school youth culture confirmed the marginal status of contemporary Alternative teenagers within the (North American) high school ecology, but also describes how membership partially separates and protects them from the wider peer-group hierarchy [29].

If we assume the link between (sub)cultural identity and self-harm is robust then how can we explain the additional risk it confers? Social contagion is often invoked as the explanation for this. This refers to the rapid transmission of behaviours from one person to others via social mechanisms and is usually indicated by the clustering of behaviours within specific social groups [30, 31]. It has been reported that 73% of females and 57% of male adolescents who self harm (i.e. with or without suicidal motivation) also have a friend who does so [32] and 82.1% of adolescent inpatients with NSSI reported having a friend who self-injured as well [33]. A recent review of NSSI social contagion confirmed the phenomena in at least 16 studies [34] and identified three mutually compatible mechanisms which may also explain the ‘Alternative-identity effect’. The first proposed mechanism is Assortive relations (or selection). Here it is suggested that Alternative teenagers predisposed to self-harm are attracted to subcultures with disturbing and emotional themes that mirror their own experience. The other proposed explanations are direct imitation, e.g. Alternative teenagers copy their self-harming friends and indirect imitation or media influence, e.g. Alternative teenagers mimic subcultural icons’ self-harming behaviours. From a sociological standpoint Alternative teenagers’ nonconformist nature predisposes them to a greater acceptance and understanding of atypical behaviours, which may include one or more forms of self-harm. A further possibility is that the additional risk is a statistical artefact, i.e. once we adjust for key risk factors linked to a nonconformist identity such as “victimisation” the alleged effect will lessen or even disappear.

Aims

This study explores the Alternative-identity effect among contemporary youth and has four specific aims: 1) to replicate past findings linking Alternative teenagers with self-harm (suicide or NSSI) in a contemporary German sample; 2) to determine if other contemporary youth identities are linked with self-harm, either as a risk (Nerd) or protective (Jock) factor; 3) to ascertain if the reasons for NSSI are different to those of Non-Alternative teenagers; 4) to determine if Alternative teenagers’ elevated risk of suicide and NSSI is (partially or wholly) accounted for by known sociodemographic risk factors (e.g. gender, socioeconomic status, migrant) or by victimisation.

Sample details

The participants were 452 German ninth-grade students from 10 schools (30 classes) located in and around the city of Ulm who took part in an anonymous study of attempted suicide and NSSI. Only students who provided both parental (written) and individual (verbal and written) consent participated in the study. Of 748 eligible students, 656 were present at the day of assessment and 452 (68.9%) of the students and their caregivers consented to take part in the study. Information on non-consenting participants is not available as German school regulations forbid the release of student data without consent. The majority of students were aged 14 (n = 112) or 15 (n = 298) although a few were older (age 16, n = 37; age 17, n = 3; missing, n = 2) and 46.2% (n = 209) were female. More than half (n = 249) of students provided information on experience of victimisation in the optional sociometric section. The study was approved by the Institutional Review Board of the University of Ulm and by the local school authorities. Students with self-harm and emotional problems could access help directly from the study team (contact card) and from external sources (local services and information card). However, no students chose to do so.

Measures

Self-harm (attempted suicide, suicidal ideation and NSSI)

Self-harm was assessed using the Self-Harm Behavior Questionnaire (SHBQ) [37], which is a self-report measure to assess the lifetime prevalence of self-harming behaviours including NSSI (‘Have you ever hurt yourself on purpose? [e.g., scratched yourself with fingernails])’ suicidal ideation (‘Have you ever talked or thought about committing suicide?’), and attempted suicide (‘Have you ever attempted suicide?’), see Table 1. The instrument is validated (Cronbach's α between 0.89-0.96 for 4 subscales) and has been used with both American and German adolescent community samples [3, 38]. The German version [39] has also been validated (Cronbach's α between 0.87-0.96). Students also completed the functional Assessment of Self-injury (FASM) instrument which asks about recent (past 12 months) engagement in 12 different forms of NSSI, e.g. ‘cut or carved your skin’. Engaging in any form of NSSI within the last 12 months was classified as recent NSSI. The FASM and SHBQ use a similar method to count the number of acts of self-injury. Students indicated how many acts of self-harm they had engaged in, truncated at ‘4 or more’ acts.

Reasons for self-injury

The FASM contains 22 items which focus on individual motives for NSSI, all measured on a 4-point frequency (‘almost never’ to ‘almost always’) scale [22]. The instrument possesses reasonable psychometric properties (Cronbach's α 0.65–0.66) [40] and has been used with both English [33, 41] and German speaking samples [42, 43].

Youth culture

Students were asked how much they identified with 18 different youth cultures (e.g. Goth, Emo, Hip-hop, etc.) using a 5-point identity scale ('not at all', ‘a little or mildly’, ‘moderately’, ‘strongly’, or ‘I am one’). The scale was translated into German from an existing questionnaire [9, 44] and updated to include contemporary subcultures. Students who identified at least ‘mildly’ as Goth, Emo, or Punk were classified as ‘Alternative’. Nerd and Jock ‘peer-crowd’ identity was measured on the same 5-point scale. Due to the frequency distribution Nerd and Jock identities were collapsed into a three categories (none, mild, moderate to complete identification, see Table 1).

Statistical analysis

Analysis was performed with SPSS 21 using descriptive statistics and both parametric (t-tests) and non-parametric (χ2, Mann–Whitney U exact) inferential statistics. When appropriate, unadjusted p-values and those adjusted for multiple comparisons (Benjamini-Hochberg method) are presented. Correlations were used to assess the strength of association between different identities and different forms of self-harm (attempted suicide, suicidal ideation or NSSI). Differences between Alternative and Non-Alternative youth about motivations for NSSI were determined via t-tests and Mann–Whitney U tests. Principle components analysis with varimax rotation was used to identify factors in the FASM and youth culture questionnaires. Multivariate logistic regression was used to assess the strength of association (odds ratios) between youth identity and different types of self-harm. Estimates from unadjusted models and those adjusted for Jock identity, gender, socioeconomic status, immigrant background and school type were compared. A final model further adjusted for the impact of victimisation. No adjustment for the clustered (school) nature of the data was made due to the small number of schools involved and because estimates of the ICC school effect for all outcomes was extremely low (≤0.02); this is consistent with the literature on school effects on suicide and self-injurious behaviours [45].

Sample statistics and demographics

Basic descriptive statistics and demographic characteristics are shown in Table 1. The rates of both attempted suicide (4.2%) and suicidal ideation (25.5%) are typical for an adolescent sample. The rate of NSSI varied according to the instrument; the SHBQ provided a lower ‘lifetime’ rate (20.7%) than the FASM ‘12 month’ prevalence estimate (45.7%). Alternative adolescents were significantly more likely to engage in NSSI (SHBQ, 45.5% vs. 18.8%; χ2 = 13.1, df 1, p < 0.001; FASM, 75.0%; vs. 43.1%, χ2 = 12.1, df 1, p < 0.001), attempt suicide (17.2% vs. 3.3%; χ2 = 12.8, df 1, p < 0.001), or think about attempting suicide (51.9% vs. 23.9%; χ2 = 10.2, df 1, p < 0.001) than Non-Alternative students.

Association between self-harm outcomes

All self-harm outcomes were significantly correlated, although the magnitude of the association varied considerably (see Additional file 1: Table S2). NSSI, as measured by SHBQ and FASM, were highly correlated (r = 0.49), as were their measures of NSSI frequency (r = 0.75). The associations between NSSI and attempted suicide were of a moderate to small effect size (SHBQ, r = 0.29; FASM, r = 0.17), as were the associations between NSSI and suicidal ideation (SHBQ, r = 0.29; FASM, r = 0.27). The correlation between attempted suicide and suicidal ideation was low (r = 0.17), but is consistent with psychometric studies of the SHBQ [37].

Factor analysis of the youth culture questionnaire

Factor analysis of the FASM

Motivation for NSSI among alternative and non-alternative youth

Association between different youth subcultures and self-harm

Association between youth subcultures and self-harm adjusting for covariates

Youth identity and self-harm

In contrast to the Alternative-identity effect, a ‘Jock’ identity is somewhat protective against self-harm. This may be attributable to a combination of their high peer-status [27, 29, 48] and regular physical exercise [9], both linked to improved psychological health [49]. This finding is in line with research showing that a positive coping style is negatively associated with NSSI [50]. Surprisingly, and counter to our predictions, identifying as a Nerd is unrelated to indicators of psychological health such as NSSI, suicidal ideation or attempted suicide. This indicates a shift upwards from their previously marginalised status and demonstrates it is possible to improve the reputation of even a heavily stigmatised adolescent identity within a generation [51, 52].

The association between different forms of self-harm and Alternative identity appears robust irrespective of its nature. However, there are qualitative differences between suicidal and NSSI, with the later the main focus of our study. Accordingly, one of our key aims is to understand ‘why’ Alternative teens engage in NSSI. Not only do Alternative youth self-injure more often than non-Alternative teens, their underlying motivations are different to other self-injurers. Alternative teenagers engage in more frequent acts of self-injury, have stronger motivation to self-injure (i.e. score higher on all but one of the FASM motivation for self-harm items) and frequently endorse both automatic and social reasons for self-injury. While Alternative teenagers are more likely to use self-injury to communicate distress or seek help they frequently self-injure to regulate their emotions. Thus, the stereotype of attention seeking Goth or Emo teenagers is only partially supported. Alternative teenagers are more likely to use self-injury to ‘belong to a group’ and ‘to avoid being with people’. Although speculative this pattern implies a strong in/out-group outlook is prevalent within Alternative youth culture with self-injury perceived by a minority of Alternative teenagers as a defining group characteristic. This is compatible with a social or self-identity interpretation of the phenomena.

Youth identity and peer contagion of self-harm

Having established that the Alternative-identity connection with self-harm is robust and eliminated the idea that this is merely an artefact attributable to social background. How do we integrate this work into current theoretical models of self-harm and social contagion? Our study is in part exploratory and thus is not conclusive in its findings. That said, we can speculate about the potential mechanisms that may explain the strong Alternative-identity effect we report. Without longitudinal data it is difficult to justify favouring any one social contagion mechanism [34], but in general our results are more consistent with the assortive relations mechanism. The repetitive nature, severity of self-harm and its key role in regulating emotions is probably underpinned by neurobiological individual differences [23, 53] rather than peer influence. The stereotypical ‘Alternative teen’ temperament and personality profile, i.e. an introverted, neurotic, impulsive, risk-taker with nonconformist tendencies [7] features several known personality risk factors for NSSI [54]. For example, openness to experience (nonconformity) predisposes individuals to experiment with different coping strategies, including self-injury [55]. High levels of neuroticism are also linked to NSSI [56, 57]. Feelings of loneliness, isolation and alienation from peers and wider society are all major components of contemporary suicide and self-injury theories [58–60]. It is premature to dismiss the role of direct or indirect imitation given that a minority of Alternative teenagers report they self-injure in order to ‘belong to a group’. The two key question for researchers investigating social modelling [34] are firstly to determine if such influence is primarily direct (peer-group) or indirect (media), and secondly to establish what proportion of ‘social self-injurers’ progress to engaging in more severe or chronic self-injury; if the proportion is high then further study is a priority.

The clustering of self-harm among Alternative youth may paradoxically indicate that membership serves several positive psychological functions and ‘belongingness’ to a certain youth group could be viewed as protective [61]. Firstly, given isolation, alienation, social disconnection and ‘thwarted belongingness’ are major predictors of self-harm, identifying with a group who share similar interests and values should reduce alienation and may help buffer the effects of low peer status and stigmatisation [29]. Secondly, from a developmental perspective, establishing a personal identity and a set of core personal values - as distinct from one’s parents - is a critical life-stage and belonging to the (Alternative) peer group may perform a key role in developing a sense of independence, mastery and control [62]. Thirdly, given the personal characteristics ascribed to Alternative teenagers such as intelligence, nonconformity and creativity, but also introversion and a melancholic and morbid outlook [7] their peer group provides an environment in which such characteristics can be expressed without stigma. For example in most schools scholastic ability is associated with low peer-status [48], while within the Alternative subculture it (alongside intelligence) is valued [7, 28, 63]. Similarly low self-esteem is a putative NSSI vulnerability factor [64] and group membership arguably boosts self-esteem [65]. This disconnect from wider peer norms may explain the strong social role that NSSI serves within the Alternative peer group, both to separate it from other groups, e.g. ‘avoid being with people’ and as characteristic in-group feature for some, e.g. ‘to belong to a group’. Finally, the strong communicative function of NSSI suggests self-injury is regarded as a valid method of soliciting help from other members of the group during periods of psychological distress. This may have mixed consequences, both facilitating help-seeking behaviour and unintentionally reinforcing self-injurious behaviour.

Limitations, recommendation for future research and clinical implications

This study has a number of methodological limitations. The cross-sectional nature of the study limits our ability to make causal inference. The moderate sample size, relatively small number of Alternative teenagers and the brief nature of assessment suggest the study has modest statistical power. The lack of available information on missing data restricts our ability to generalise our findings to pupils unable or unwilling to participate. Our reliance on self-report means we may have somewhat reduced reliability regarding self-harming behaviours (see below) or social confounders, but is irrelevant for self-identity measures. Our measure of subcultural identity needs further validation. This is inherently problematic given the shifting nature of youth culture and while some youth cultures are relative stable any measure of subcultural identity will require adaptation to local context.

Surprisingly, the FASM 1-year NSSI prevalence (45.7%) is higher than the lifetime NSSI rate provided by the SHBQ (20.7%), yet this counterintuitive finding is attributable to its longer length, the more comprehensive list of self-injury methods included in the FASM and is consistent with previous findings. While we have explored how Alternative youth differ in their motivations for NSSI, we have not explored their motivations for suicide. It remains to be established which of the two common methods of measuring subcultural identity, factor scores or categorical measures, is superior. Importantly, our findings are robust irrespective of the method used. Despite these limitations the ability to link subcultural affiliation with a number of features of self-harm, particularly motivations, is novel and provides further insight into the nature of the relationship.

Future work should explore if this is exclusively a western phenomena, although the existence of similar ‘dark’ and morbid but non-western subcultures such as Gothic Lolita [66] (membership of which has been anecdotally linked with psychological trauma [67]) suggests not. Complimentary qualitative and mixed methods studies could provide invaluable ‘in depth’ insights into the social and personal motivations of Alternative teenagers suicidal and self-injuring behaviours than psychometric measures alone. We extended this research topic by incorporating the peer crowd (e.g. Jocks and Nerds) framework and this requires replication. In the light of our reversal of ‘Nerd’ subculture from marginalised to revered status finding, a time series analysis of the Alternative-identity effect is warranted to determine if the effect is stronger among particular generations.

Another key question is related to intervention; given that the Alternative-identity effect is one of the largest effects thus found in NSSI research, is it possible to design peer-group appropriate interventions? One intervention involves knowledge exchange and training to assist educators in understanding the nature and function of different youth subcultures. At least two organisation use this form of intervention; the UCLA Center for Mental Health in Schools [68] and the Sophie Lancaster Foundation [69], with the former aiming to improving mental health and the latter aiming to reduce victimisation. Peer-based interventions for smoking prevention use social learning mechanisms; by training popular ‘peer-leaders’ to disseminate anti-smoking information they capitalise on modelling behaviour and peer status [70]. Given the strong link between self-harm and peer affiliation [71] this intervention model may be particularly effective in relation to self-injury, but could unintentionally aggravate NSSI social contagion. Clinicians may consider treatments which complement adolescents’ existing peer identities: we speculate that such ‘matching’ may improve treatment effectiveness. For example, although the effectiveness of music therapy in treating NSSI is unproven, Alternative teenagers are particularly receptive to this form of treatment [43] and it follows that ‘Nerds’ may be more receptive to online [72] and Jocks to exercise-based intervention [73]. Others see identifying adolescents particularly vulnerable to social contagion as a priority [34] and identifying the minority of teenagers who use self-injury as a marker of identity is a related priority.