Introduction

In the last decades, the interest in studying resources and strengths in individuals with autism spectrum disorder (ASD), in contrast to the mere study of symptoms and deficits, has grown. This is especially relevant because outcomes (e.g., satisfaction with life, employment) in adults with ASD are often poor and rates of comorbid depression are high (Howlin and Moss 2012). Strengths-focused research can inform interventions targeting improvements of outcomes in adults with ASD. Strengths in some individuals with ASD have been described so far in three different contexts: (1) abilities related to a specific cognitive style (Dawson et al. 2007), (2) skills related to special interests (Kirchner and Dziobek 2014) and (3) positive aspects related to personality and character (Preißmann 2014).

In the current paper, we sought to address the third area of potential strengths in ASD, namely those related to personality characteristics. There are anecdotal descriptions of individuals with ASD having certain strengths associated with their personality, such as being fair, authentic and reliable (Preißmann 2014). Also Attwood and Gray (1999) described individuals with ASD as loyal friends who speak their mind “irrespective of social context or adherence to personal beliefs”, are free of sexist, ageist, or culturalist biases and have an inherent determination to seek the truth. There have been scientific attempts to describe personality beyond mere psychopathology in ASD (Ozonoff et al. 2005; Strunz et al. 2014); however, the focus was often on weaknesses rather than strengths (Schriber et al. 2014).

A new perspective on personality is taken by positive psychology, which offers a theoretical framework to study character strengths as supplement to the study of deficits and disorders in traditional psychology (Park and Peterson 2009). Character strengths are defined as positively valued trait-like individual differences, which manifest in individuals’ thoughts, feelings, and behaviours across different situations and are stable over time. In a first study comparing individuals with ASD and neurotypical (i.e., non-autistic) controls regarding their character strengths with the Values in Action Inventory of Strengths, (VIA-IS, Peterson and Seligman 2004) Samson and Antonelli (2013) found the ASD group to score mostly lower on emotional and interpersonal character strengths but as high on most intellectual strengths and strengths of restraint as the control group. However, rather than only comparing magnitudes of character strengths of individuals with ASD to a norm population (Samson and Antonelli 2013), it was suggested that in vulnerable populations it is more warranted to examine an individual’s strengths relative to his/her other strengths of character (Park and Peterson 2009). With this individual strength-based approach, the focus is on those strengths, which the individual possesses, rather than on differences from others. In particular, the five top-ranked strengths in one´s strength ranking, also referred to as signature strengths, have received growing research attention, as they are considered to be the most salient to a person (Peterson and Seligman 2004; Ruch et al. 2010).

Another influential line of research regarding character strengths provides growing empirical evidence in neurotypical individuals, that the endorsement of character strengths is positively associated with satisfaction with life (SWL) (Littman-Ovadia and Lavy 2012). It has been shown that training those character strengths which were associated with SWL—compared to others which were not- improves SWL (Proyer et al. 2013). However, groups of individuals (e.g., different cultures/occupations/genders) seem to differ regarding which character strengths are most strongly associated with SWL (Littman-Ovadia and Lavy 2012; Peterson et al. 2007).

In the current study we (1) assessed character strengths in individuals with ASD and neurotypical controls, (2) examined which character strengths are most often signature strengths in individuals with ASD and explored differences from controls and (3) explored associations between character strengths and SWL in individuals with ASD and controls.

Methods

Participants

Thirty-two adults with ASD without intellectual impairment and 32 matched (gender, age, education and employment status) neurotypical controls were included in the study. Subjects with ASD were recruited through the autism outpatient clinic of the Charité—University Medicine Berlin or were referred by specialized cooperating clinicians. All participants were diagnosed with an ASD according to DSM-IV (American Psychiatric Association 2000) using the Autism Diagnostic Observation Schedule (ADOS, Bölte and Poustka 2004) and a semi-structured clinical interview based on the Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV, American Psychiatric Association 2000). Assessment was done by a trained clinical psychologist and a specialized medical doctor. For demographic data, see Table 1.

Table 1 Demographics
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Measures

The Values in Action Inventory of Strengths (VIA-IS, Peterson and Seligman 2004) is a self-report questionnaire assessing 24 character strengths, which can be assigned to five factors (emotional, interpersonal, intellectual and theological strengths, as well as strengths of restraint) (Ruch et al. 2010). For the VIA-IS character strengths and descriptions, see Table 2. Each scale consists of ten items. In total the VIA-IS contains 240 items, which are rated using a five-point Likert scale (1 = “very much unlike me” to 5 = “very much like me”). An example item for the character strength persistence is “I never quit a task before it is done”. Mean scores for the scales are calculated. In this study, the German version of the VIA-IS was used (Ruch et al. 2010). It demonstrated to be reliable and valid: internal consistencies of the scales ranged from Cronbach’s α = .71 to .90 (Ruch et al. 2010). In our study, internal consistencies of the scales ranged from Cronbach’s α = .70 to .91 (ASD) and α = .84 to .93 (controls).

Table 2 The 24 Character Strengths included in the Values in Action Inventory of Strengths (VIA-IS, Peterson and Seligman 2004) and short descriptions (Ruch et al. 2010, Harzer and Ruch 2014)
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The Satisfaction with Life Scale (SWLS: Diener et al. 1985) is a five-item instrument measuring global life satisfaction using a seven-point Likert scale (1 = “strongly disagree” to 7 = “strongly agree”). An example item is “I am satisfied with my life”. A mean score is calculated. The SWLS is widely used in research and has shown strong internal reliability (Cronbach’s α = .87) (Diener et al. 1985) and good discriminant validity (Pavot and Diener 1993). In the present study, Cronbach’s α were .80 (ASD) and α = .88 (controls).

Procedure

Participants with ASD completed the questionnaires online and received 15 €. A matched control group was randomly selected from a large data pool which was collected through the website www.charakterstaerken.org hosted by the University of Zürich. All questionnaires were completed anonymously. All parts of the study were conducted according to the declaration of Helsinki and following local ethical standards. All subjects provided written informed consent. Statistical analyses were performed with the statistical software IBM SPSS 22. Accounting for multiple testing, corrected levels of significance were administered using the false discovery rate procedure proposed by Benjamini and Hochberg (1995).

Results

Group Comparisons Mean Scores VIA-IS

Multivariate analysis of variance with the 24 scales of the VIA-IS as dependent variables and group (ASD/control) as the fixed factor were computed. All assumptions for conducting a MANOVA were met. There was a significant main effect of group, indicating that individuals with ASD and controls differed regarding the endorsement of character strengths, F(24, 39) = 5.36, p < .001; Wilk’s Λ = .23, partial η2 = .77. For a full display of results, see Table 3.

Table 3 Character strengths in individuals with ASD and neurotypical control individuals
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Ipsative Ranking and Signature Strengths

We assigned ipsative ranks to individual strengths scores, from 1 (highest) to 24 (lowest), resulting in a specific ranking order for each participant. Based on that ranking, we identified the five most highly ranked strengths for each individual (which are referred to as signature strengths) and calculated percentages for how often a certain strength belonged to the signature strengths in each group (see Table 4).

Table 4 Ranking of signature strengths
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To reveal group differences between these percentages, we conducted chi square tests (see Littman-Ovadia and Lavy 2012) for those strengths that were ranked within the top five for at least one of the groups (open-mindedness, authenticity, love of learning, creativity, fairness, humour, kindness, love). Creativity was significantly more often a signature strength in ASD (χ 2 (1, N = 64) = 5.74, p = .02) than in controls, while love (χ 2 (1, N = 64) = 5.85, p = .02) and humour (χ 2 (1, N = 64) = 10.47, p < .01) were significantly more often signature strengths in controls. There were no significant differences between groups regarding the other character strengths.

Satisfaction with Life and Character Strengths

Satisfaction with life was significantly lower in ASD (M = 2.9, SD = 1.2) than in controls (M = 4.5, SD = 1.4), t (62) = 4.76, p < .001). Pearson correlations with the 24 character strengths of the VIA-IS and the SWLS were conducted. Descriptively, the two groups had the strongest associations between hope and zest with SWL, respectively. In addition, kindness, social intelligence, teamwork and humour were most strongly related to SWL in ASD, while for controls persistence, curiosity, perspective, and humour were most strongly correlated with SWL. For a complete display of correlations, see Table 5.

Table 5 Correlations between VIA-IS character strengths and SWLS
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Discussion

Endorsement of Character Strengths

The ASD group scored mostly lower on those character strengths that can be classed as interpersonal (e.g., teamwork, kindness) and emotional (e.g., social intelligence, love) strengths but did not differ from controls on most intellectual strengths and strengths of restraint, which is in line with Samson and Antonelli (2013). This also corroborates a study from Strunz et al. (2014), who assessed individuals with ASD without intellectual impairment using the NEO Personality Inventory-Revised (NEO-PI-R) and found them to be as intellectually curious, as dutiful and to strive as much for achievements as controls. We found open-mindedness to be the highest ranked character strength in ASD, but in contrast to Samson and Antonelli (2013) we did not find individuals with ASD to score higher on open-mindedness than controls.

Signature Strengths

In ASD, the most frequent signature strengths were open-mindedness (intellectual strengths), authenticity (strength of restraint), love of learning (intellectual strength), creativity (intellectual strength), and fairness (interpersonal strength). In comparison, open-mindedness (intellectual strength), fairness (interpersonal strength), humour (emotional strength), kindness (interpersonal strength) and love (emotional strength) were most often in the signature strengths profile of controls.

Individuals who score high on open-mindedness think things through, examine aspects from all sides, weigh the pros and cons carefully and do not jump to conclusions impulsively (Harzer and Ruch 2014). Following the theory of systemizing (Baron-Cohen et al. 2003), individuals with ASD seek to discover the “truth” by looking for lawful patterns and they are more likely to base their judgment on rules (e.g., weighing pros and cons) rather than on information which comes from empathizing (Baron-Cohen 2009). Also, fairness and authenticity, which are within the most typical signature strengths in individuals with ASD, can be facilitated by the trend to systemize. Fairness consists of treating all people the same according to principles of fairness and justice, and individuals who endorse the character strength authenticity speak the truth and present themselves in a genuine way (Harzer and Ruch 2014). There are anecdotal reports that individuals with ASD adhere to social rules in a deterministic way (such as sharing things equally or telling the truth). More evidence towards strengths in authenticity and fairness in individuals with ASD comes from other studies. Izuma et al. (2011) found individuals with ASD to be less likely to adapt their behaviour in order to improve their social reputation than neurotypical controls and we found individuals with ASD to have fewer social stereotypes against ethnic minorities compared to a neurotypical control group (Kirchner et al. 2012). Another character strength belonging to the most frequent signature strengths in individuals with ASD—and significantly more often than in controls—was creativity. Individuals who endorse creativity as a character strength consider themselves as original thinkers and like to come up with new and different ideas (Harzer and Ruch 2014). Empirical evidence regarding creativity being a strength in individuals with ASD comes from a study from Liu et al. (2011), who found them to score higher on originality and elaboration. In addition, in a previous study we identified creativity as the second most common approach in pursuing one’s special interest (after systemizing) in individuals with ASD (Kirchner & Dziobek 2014). The fifth character strength, which belonged to the most common signature strengths in individuals with ASD, was love of learning, which comprises the eagerness to master new skills, topics and bodies of knowledge (Harzer and Ruch 2014). Already Asperger (1944) described individuals with ASD to be able to acquire an astonishing body of knowledge in their special interests, often through self-guided studying.

Character Strengths and Satisfaction with Life

Interestingly, we found hope, zest, kindness, humour, social intelligence and teamwork (all emotional or interpersonal strengths) to have the strongest positive associations with SWL in the ASD group. This is in contrast to Samson and Antonelli (2013), who found only hope to be associated with SWL in ASD.Footnote 1 One possible interpretation is that higher levels of emotional and interpersonal strengths contribute to higher SWL in ASD, which would underline the importance of training social and emotional competencies in this population. In line with that, Mazurek (2014) found loneliness to be associated with decreased levels of SWL in ASD, while greater quantity and quality of friendships were associated with decreased loneliness.

In addition to the importance of certain character strengths for SWL, it is also fruitful to consider the fit between environment and tasks (e.g., at work) with the character strengths of an individual. For example, Harzer and Ruch (2012) found neurotypical individuals who applied their signature strengths at work to report more positive experiences. Thus future studies should evaluate how exercising character strengths, and signature strengths in particular, can contribute to the improvement of outcomes (e.g., SWL, work satisfaction, etc.) in ASD.

The results of this study should be interpreted with the following limitations in mind: All collected data are self-reported data. For future studies we recommend to also use a peer-rating form for the character strengths questionnaire (Ruch et al. 2010). The size of our research sample was relatively small, which limits the generalization of the findings. Furthermore, we might have missed effects between groups due to limited statistical power and no causational inferences can be drawn due to the cross-sectional design of our study.