Aspectos Conceptuales

The Ultimatum Game (UG) is an economic decision-making game that has been used as a measure emotion regulation (Crockett et al., 2008; Guth et al., 1982; Koenigs & Tranel, 2007; Koenigs et al., 2010). In this paradigm two players are given the opportunity to split a sum of money. One player (the proposer) proposes a way to split an amount of money with another player (the responder). These offers vary in fairness and the participant must simply accept or reject the offers made to them. If the responder accepts the offer, both players are

paid accordingly. If the offer is rejected, neither player is paid. Traditional economic models regard decision-making as a rational, cognitive process (e.g. utility theory; Fishburn, 1970) and state that all offers, irrespective of their fairness, should be accepted. However, this is not what is observed; studies find that comparatively small - and therefore unfair offers (20% of the total) - have a 50% chance of being rejected (Bolton & Zwick, 1995; Guth et al., 1982).

Traditional economic models have been challenged by behavioural economists, who identified additional factors that influence decision-making (Gospic et al., 2011; Loewenstein & Lerner, 2003; Sanfey et al., 2003). It has been suggested that the rejection of unfair offers is best explained by negative emotions, such as anger and frustration, that drive participants to penalise rather than making an utilitarian choice (Fehr & Gachter, 2002; Pillutla & Murninghan, 1996). Rejection of unfair offers has been associated with an increase in amygdala activity (Gospic et al., 2011) and anterior insula activity (Sanfey et al., 2003) - traditionally correlated with feelings of anger and disgust (Calder et al., 2001; Phillips et al., 1997) - and autonomic activation (skin conductance; van’t Wout et al., 2006). These results suggest that the (irrational) rejection of unfair offers is driven by emotional responses to unfair treatment and that the ability to regulate negative emotions may be essential for the rational acceptance of unfair offers.

Results from studies examining children and adults converge to suggest that age is an important factor in emotion regulation in the ultimatum game. A consistent finding is that there is a U-shaped developmental trajectory: adolescents reject more unfair offers than younger children and adults (Harbaugh et al., 2003; Hoffman & Tee, 2006; Murnighan & Saxon, 1998), which is consistent with the conceptualization of a peak in emotional reactivity during adolescence (Brenhouse & Andersen, 2011).

Moreover, individuals who are poor at regulating emotions tend to make more

irrational decisions (i.e., reject more unfair offers) in the UG (Koenigs & Tranel, 2007). Men with higher manipulated levels of testosterone (Zak et al., 2009) and patients with VMPFC damage reject more offers (Koenigs & Tranel, 2007). Interestingly, although children high in psychopathic CU traits do not show consistent regulatory problems (Frick & Morris, 2004), Koenigs et al. (2010) observed poorer regulation during the UG in low-anxious psychopathic offenders in comparison with high-anxious psychopathic and non-psychopathic offenders. This might indicate that there is variation in UG performance within ASB groups, specifically in relation to psychopathic traits; however, due to the small sample sizes (n=6) and lack of a non-ASB control sample, further research is needed to clarify this issue.

Although emotion dysregulation can affect economic and social decision-making, there are other factors that can influence decision-making behaviour. Doya (2008)

emphasized the role of the individual’s economic needs and perception of gains and losses, with these factors influencing the satiety to the reward. Neuroeconomic methods, which include paradigms such as the UG, highlight that reward-processing brain regions are active during decision-making (Sharp et al., 2012). Both adolescents and antisocial samples seem to be highly sensitive to rewards. Van Leijenhorst and colleagues (2010) found an adolescent- specific peak in activation of the VMPFC and ventral striatum during risky choices and the processing of reward in a decision-making paradigm, suggesting increased sensitivity to rewards during adolescence. Moreover, numerous studies using decision-making tasks have demonstrated a relationship between reward dominance – that is decision-making in favour of rewards, irrespective of punishment – and externalising problems in samples of adolescents with psychopathic tendencies, and children and adolescents with oppositional defiant disorder and conduct disorder (Fisher & Blair, 1998; Fonseca & Yule, 1995; Matthys et al., 1998; Newman & Kosson, 1986; Newman et al., 1990; O’Brien & Frick, 1996; van Goozen et al.,

2004). Based on this evidence, it is possible that adolescents in general, and ASB adolescents in particular, might accept more unfair offers compared with those in other age groups, or those who do not engage in ASB.

While ASB individuals in general seem highly driven by reward (Fisher & Blair, 1998; Fonseca & Yule, 1995; Matthys et al., 1998; Newman & Kosson, 1986; Newman et al., 1990; O’Brien & Frick, 1996; van Goozen et al., 2004), there is variation in reward

sensitivity within ASB individuals. Violent adult offenders preferred smaller immediate rewards over larger delayed rewards compared to their non-violent counterparts (Cherek et al., 1997). This evidence suggests that more serious (i.e., violent) offenders might accept more ‘unfair’ offers in the UG in comparison with less severe offenders. If reward seeking drives decision-making, offence severity could help to explain variation in offenders’ responses to the UG, predicting greater acceptance of unfair offers.

Lack of affective empathy, which has been theorised to be implicated in ASB, particularly psychopathic forms (Joliffe & Farrington, 2004), may also have influenced the decision-making. Individuals, who lack empathy and care less about others, are likely to be less driven by anger and the motivation to punish the other individuals. Based on the finding that psychopathy is associated with a specific deficit in affective empathy (Blair, 2005b; Dadds et al., 2009), as well as results from a meta-analysis of 35 studies that violent offenders have less empathy than non-violent offenders (Jolliffe & Farrington, 2004), one might expect psychopathic and violent adolescent offenders to empathise less with others and to be less motivated to reject ‘unfair’ offers.