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Research Spotlight

How Atypical Sexual Interests Develop: Biology, Experience and the Online Environment

What We Looked At

This review examines what current evidence tells us about how atypical sexual interests develop. It draws on research from neuroscience, developmental psychology, attachment theory and media studies to explore the relative contributions of biological predisposition, early life experience, conditioning processes and online exposure.

A key concept running through the review is neuroplasticity: the brain’s capacity to adapt and reorganise in response to repeated experiences, thoughts and behaviours (Been et al., 2022). This provides a mechanism for understanding how biological vulnerabilities and environmental influences interact over time to shape sexual interests, particularly during adolescence.

Importantly, the review distinguishes between paraphilia – an atypical sexual interest – and paraphilic disorder, where that interest causes clinically significant distress, impairment or harm to others (American Psychiatric Association, 2013). Many people report atypical sexual interests without meeting the threshold for a disorder (Joyal, 2015; Joyal, 2018), and conflating the two risks reinforcing stigma and discouraging people from seeking support. It is important to distinguish between ‘atypical’ or ‘deviant’ and ‘harmful’ as different concepts when thinking about and discussing sexuality (Bering, 2013).

What the Research Found

Biological factors create vulnerability, but are not deterministic. Research points to the role of brain regions involved in reward, impulse control and emotional regulation – including the ventral striatum, prefrontal cortex and amygdala – in shaping how individuals respond to sexual stimuli (Costumero et al., 2013; Seok et al., 2016). The Dual Control Model (Bancroft & Janssen, 2000) proposes that individual differences in sexual behaviour reflect a balance between excitation and inhibition systems, and that some people may be biologically predisposed to stronger arousal responses or weaker inhibitory control. Genetic factors may influence traits such as reward sensitivity and impulsivity, though direct evidence for a heritable component in atypical sexual interests remains limited (Shim et al., 2014).

Neurodevelopmental differences are relevant but not causal. Young people with ASD or ADHD may have differences in brain connectivity and dopaminergic pathways that influence the balance between excitation and inhibition (Silvertant, 2018; Wilkins, 2024). In ASD, sensory sensitivities and patterns of focused attention may shape how sexual stimuli are processed (Schöttle et al., 2017). In ADHD, impulsivity and novelty-seeking may influence patterns of sexual behaviour or exploration (Turner et al., 2025). These are better understood as factors that influence vulnerability or expression, rather than as causes in themselves. The empirical evidence directly linking ASD or ADHD to atypical sexual interests remains limited and often based on small or clinical samples (Young & Cocallis, 2023).

Puberty is a critical window. The hormonal changes of puberty amplify sensitivity to sexual stimuli and increase the brain’s neuroplasticity, meaning that neural pathways are more easily shaped during this period through repeated patterns of reward and arousal (Fortenberry, 2013; Been et al., 2022). Biological predispositions may become more pronounced at this stage, potentially shaping the emergence of both typical and atypical interests. Adolescence is therefore a period of particular importance for both risk and intervention.

Early adverse experiences play an important role. Research consistently identifies links between early childhood abuse, attachment disruption and the later development of problematic sexual thinking and behaviour (Davis & Knight, 2019; Leroux et al., 2020). Insecure attachment formed in early relationships may create ongoing difficulties with emotional regulation and intimacy, which in some cases may lead individuals to seek alternative ways of meeting emotional needs (Bowlby, 1969; Ainsworth, 1978; Wizła & Lewczuk, 2024). However, much of this evidence comes from forensic or clinical samples i.e. populations of people who have already come to the attention of services, which limits what it tells us about the wider population who have experienced adversity but have not gone on to cause harm.

Repeated cognitive rehearsal can reinforce atypical interests over time. Research suggests that repeated engagement with sexual fantasies may strengthen associations between specific stimuli and arousal, potentially through neuroplastic processes that consolidate neural pathways (Tews, 2020). This provides a plausible mechanism by which particular patterns of thinking or behaviour, once established, become maintained, and underlines the value of intervening early, before these pathways become more fixed.

Online exposure interacts with existing vulnerabilities. Digital environments now provide unprecedented access to a wide range of sexual content during childhood and adolescence (Ofcom, 2025), a period characterised by heightened neuroplasticity and reward sensitivity. Around 8% of children aged 8-14 in the UK have visited a pornographic website, with this being most common (about two in ten) for boys aged 13-14 (Ofcom, 2025). For young people with pre-existing biological vulnerabilities or adverse early experiences, repeated engagement with online sexual material may be particularly salient; reinforcing learned associations between certain stimuli and arousal in ways consistent with Social Learning Theory (Bandura, 1973; 1977). Online exposure alone is unlikely to cause atypical sexual interests, but it may interact with underlying vulnerabilities to shape how those interests develop and are maintained. The Youth Justice Board (2026) has noted a 47% rise in sexual offences by children in recent years, often involving harassment and image-based abuse, highlighting the real-world consequences of these dynamics.

What This Means in Practice

The biopsychosocial framework outlined in this review has clear implications for intervention:

• Adolescence is the key window for preventative work. Because the brain is at its most plastic during this period, interventions delivered in adolescence are more likely to shape adaptive patterns before they become entrenched (Been et al., 2022; Goulet & Tardif, 2018).
• Sex and relationship education needs to go beyond biology. Comprehensive RSE that addresses consent, emotional regulation and critical engagement with sexual content can help disrupt maladaptive conditioning processes, particularly when it is tailored to include young people with neurodevelopmental differences or histories of trauma (Alma Economics, 2024; Downs Syndrome Association, 2021).
• Trauma-informed approaches matter. For young people with adverse childhood experiences, targeted support addressing impulse control, emotional regulation and social understanding can reduce susceptibility to reinforcement processes that may otherwise compound vulnerability (Levenson, 2014; Bellis et al., 2011).
• Digital literacy is part of the picture. Improving young people’s awareness of how online content is produced, distributed and algorithmically promoted may reduce the impact of exposure, and has the benefit of reaching those who might not otherwise seek support due to stigma (Pinkleton et al., 2012; Bailey et al., 2015).
• Stigma is itself a barrier. Many people with atypical sexual interests do not have a disorder and never cause harm. Conflating atypical interests with pathology discourages help-seeking and reduces opportunities for early intervention or support. Reducing stigma in research, practice and public discourse is therefore an important goal in its own right.

Where the Research Needs to Go Next

Significant gaps remain. Much of the existing evidence relies on cross-sectional or forensic samples, which limits conclusions about causality and generalisability. There is a particular lack of longitudinal research tracking whether atypical sexual interests that emerge in adolescence persist, change or diminish into adulthood (Alexandru et al., 2023). The field also needs clearer, more consistent terminology, and greater attention to populations who have not come to the attention of services; whose experiences are currently largely invisible in the literature. Future research should prioritise prospective longitudinal designs, more diverse sampling, and the development and evaluation of evidence-based early intervention strategies.

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