Page 62 - The prevalence of the Val66Met polymorphism in musicians: Possible evidence for compensatory neuroplasticity from a pilot study

S. Si et al. NeuroImage 213 (2020) 116681
determined by a single variant of DRD2 or COMT, but combinations of between them. This to certain extent coincides with the vantage sensi-
them (CGS). They may influence creativity through their effects on DA tivity model that was newly proposed by Manuck (2011) and Sweitzer
neurotransmission. A wide range of evidence has established the role of et al. (2013). It mainly describes individuals’ different response to pos-
DA in motivation (Carlson, 2001). And a theory based on this evidence itive environments, arguing some individuals tend to be more susceptible
stating that the dopaminergic neural system may facilitate creativity to beneficial environments but are relatively unaffected by adverse sit-
through motivation (Flaherty, 2005). A recent empirical study showed uation (Pluess and Belsky, 2013). Nonetheless, a low level of father
motivation acted as a mediator between dopamine related gene and authoritarianism may not be the same as the exclusively positive envi-
divergent thinking (Takeuchi et al., 2015). These probably make us ronment described by Kegel et al., (2011). So it is still uncertain whether
speculate that DA mediated by DRD2 and COMT might influence crea- this finding has the potential to provide support for vantage sensitivity
tivity by affecting motivation or other dopamine-related cognitive pro- model. Another reason why we did not identify the interaction pattern
cess. According to Self-Determination Theory (SDT; Deci and Ryan, 2000, might be the serious skewed distribution of CGS e data in our sample.
2008), social environments (including parenting) influence individuals’ Future studies with larger sample need to retest this initial finding.
motivation which in turn, affects cognitive, affective, and behavioral In contrast to previous studies, we examined combinations of poly-
outcomes; therefore, motivation may be one of the mechanisms under- morphisms from DRD2 and COMT genes by using CGS which can help us
lying the interactive effect of CGS and parenting style on creativity. understand the dopamine cumulative effect of genetic influence. More
Future studies are warranted to test this hypothesis. concretely, we developed five CGSs consisting of two or more SNPs with
However, just as mentioned before, COMT not only affects dopamine, a consistent direction of effects with regard to a specific parenting style
but also norepinephrine (Beversdorf, 2018). Since the combined effect of that models the cumulative genetic plasticity on creativity. It helps us
norepinephrinergic and dopaminergic system were also found to mod- identify a multi-locus genetic profile that putatively influences dopamine
erate the association of environmental factors with creativity-related transmission and individual sensitivity to environment. This can to a
personality (Kazantseva et al., 2009), the present findings could not certain extent reduce multiple-testing problems of analyzing individual
exclude the possibility that both dopaminergic and norepinephrinergic polymorphisms (Docherty et al., 2011). Moreover, the present study
system may be involved in the relationship among CGS, parenting style pointed out CGS models presented here accounted for more variance
and creativity. Consequently, future studies should take into account the than did individual variants alone. This suggests even a relatively simple
effect of norepinephrinergic genes or their interactions with dopami- CGS, such as the one we created, can explain some of the genetic influ-
nergic genes in parenting style and creativity. Furthermore, it is generally ence that may have led to inconsistent discoveries in individual genetic
known that serotonin and dopamine neurotransmitters are closely variation analysis. Therefore, aggregating polymorphisms may become a
related with cognitive function, and neurotransmission mediated by se- better way to estimate genetic influence on phenotypes and could also be
rotonin transporter could be affected to some extent by DA and vice versa utilized in G E research.
(Gonza lez-Burgos & Feria-Velasco, 2008). Although there was evidence This study is not without limitations. Relatively small sample size is
that one particular serotonergic gene might act as a moderator between arguably the most important. Replication of these preliminary findings
parenting style and creativity (Zhang et al., 2018), no study has consid- with a larger sample size is clearly warranted. In addition, we did not use
ered incorporating the potential role of dopaminergic genes among them. an objective measure of the parenting style, such as observations of
Finally, creativity is a complex trait determined by multiple genes (Power parenting behaviors. Future studies simultaneously employing both the
et al., 2015), as all of the dopamine, serotonin and norepinephrine sys- subjective and objective measures of parenting style would provide more
tem are involved in creative cognitive process, it is reasonable to suppose convincing results. Also, the findings may only be generalized to diver-
the relationship between parenting style and creativity might be gent thinking. According to Guilford (1950), convergent thinking is also
moderated by interaction between all of them. a main ingredient of creativity. It is considered a process of generating
Follow up tests using the Roisman criteria provided evidence for the one possible solution to a particular problem. There was evidence that
differential susceptibility model. Compared with individuals with low the relationship between individual spontaneous eye blink rate (EBR)—a
CGS, high CGS carriers are more likely to be affected by parenting style. clinical marker of dopaminergic functioning and convergent thinking is
This is in accordance with previous studies which found the more negative (more or less linear), implying that convergent thinking is
“plasticity” allele individuals carry, the more susceptible they will be to increasingly impaired by higher dopamine levels (Chermahini and
environmental influences (Belsky et al., 2007; Belsky et al., 2009; Belsky Hommel, 2010). Therefore, in the future studies, we’d like to investigate
and Pluess, 2009). In our present study, individuals with more plasticity whether there will be a negative relationship between convergent
alleles showed higher level of creativity under conditions of high thinking and COMT/DRD2. Last but not the least, since all variants
authoritativeness or permissiveness while demonstrated lower level of included are not likely to interact with the environment equivalently,
creativity when they are experiencing low authoritativeness or permis- future research should develop weighted CGS using separate samples,
siveness. In other words, the higher CGS makes individuals more sus- and the weights for each variant used in the CGS should be determined by
ceptible to an adverse environment with low authoritativeness or the first sample (Purcell et al., 2009).
permissiveness, but also to a more favorable environment with high In conclusion, the current study provides evidence of the combined
authoritativeness or permissiveness, for creativity. The link between effect of polymorphisms from DRD2 and COMT genes and parenting style
higher CGS and increased environmental influence on divergent thinking on creativity. Furthermore, it extends these findings to suggest the pos-
is also similar to existing examples of differential susceptibility for sibility of differential susceptibility, such that the individuals with high
cognition which suggests that individuals with more susceptibility alleles CGS were more likely to be affected by their both negative and positive
are more likely to be affected by environment in a better or worse manner parenting style, demonstrating higher and lower creativity. These results
(Gibbons et al., 2012). Thus combinations of DRD2 and COMT variations further provide evidence for the involvement of dopaminergic genes (i.e.
that are associated with environmental sensitivity may moderate the DRD2, COMT) in the relationship between parenting style and creativity
extent to which an individual is influenced by his or her environment. and suggest individuals with the greater susceptibility are the ones who
Notably, the interaction pattern of CGS e and father authoritarianism are more susceptible to environmental influences.
on creativity did not conform to either diathesis-stress or genetic sus-
ceptibility model. The result of Ros analysis indicated, when experi- Declaration of competing interest
encing a low level of father authoritarianism, individuals with high CGS e
demonstrated higher level of creativity than those individuals with low The authors declare that the research was conducted in the absence of
CGS e ; however, when they are experiencing a high level of father any commercial or financial relationships that could be construed as a
authoritarianism, no significant difference in creativity was found potential conflict of interest.

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