“Bexkens et al. (2019). Peer-influence on risk-taking in male adolescent with mild to borderline intellectual disabilities and/or behavior disorder.” – Article summary

There is increased risk-taking in adolescence. Adolescent risk-taking may occur because of an imbalance in brain development with a protracted development of the cognitive control system relative to a high reactivity in the reward system. Real-life risk taking typically occurs when peers are present. Adolescents spend more time in the presence of peers and become more sensitive to the effects of peers.

Peer pressure enhances reactivity in the brain’s reward circuitry. This indicates an influence of the presence of peers on reward valence. The relationship between lower resistance to peer-influence and increased behavioural risk-taking is mediated by the right temporoparietal junction (TPJ). This is one of the core regions associated with social-cognitive processes (e.g. perspective taking). This indicates an important role of social-cognitive processes during peer influence on risk taking.

Factors related to the explanation of adolescent risk-taking are cognitive control processes (1), reactivity of the reward system (2), social cues (3) and social cognition (4).

There is increased risk taking in adolescents with mild-to-borderline intellectual disability. Mild-to-borderline intellectual disability consists of borderline intellectual functioning (i.e. IQ between 70 and 85) and mild intellectual disability (i.e. IQ between 50 and 85) and both consist of limitations in adaptive functioning. The prevalence of MBID is 10% and is heterogeneous and highly comorbid.

MBID is associated with cognitive control deficits. Adolescents with MBID struggle to make safe decisions under negative peer-pressure. There are social-cognitive deficits in MBID and this could make adolescents with MBID more vulnerable to peer-pressure because they are less able to read their peers’ intentions. Behavioural problems are associated to enhance risk-taking and it is linked to aberrant reward processing and cognitive control problems.

In the presence of peers, the presence of MBID is associated with increased risk taking and increased risk-taking propensity. This is not the case in the absence of peers. MBID but not BD is related to increased risk-taking propensity in the presence of peers. MBID was associated with lower behavioural consistency, especially in the presence of peers. This indicates that MBID and peer influence result in lower behavioural consistency.

Only having MBID (i.e. no BD) is related to increased safety estimates and MBID in general enhances safety estimates under peer pressure. Only having MBID is also associated with decreased uncertainty estimates and MBID in general decreases uncertainty estimates under peer pressure.

MBID is related to increased risk taking under peer pressure whereas BD is not associated with increased risk taking. This indicates that risk-taking may be the result of lower intellectual functioning rather than behavioural problems.

It is possible that adolescents with low resistance to peer-influence are distracted by the social implications of their decisions and, therefore, make more risky decisions. The MBID-only group is characterized by increased safety estimates and enhanced risk taking propensity. This both leads to increased risk taking behaviour.

Pro-social peers can successfully reduce externalizing behaviour. MBID-related increased real-life risk taking may be better explained by low intellectual functioning than by comorbid behavioural disorders. MBID may not result in increased risk-taking per se but in increased risk-taking propensity and estimation of safety under peer-influence, which, in turn, is believed to lead to increased risk-taking.