Abstract: The debate over “nature versus nurture” has been an intense focus of creativity research. Like most other human behaviors and complex psychological traits, the origin of individual differences in creativity could be attributed to the influence of genes and environment. By comparing the phenotypic similarity among monozygotic versus dizygotic twins, early quantitative genetic studies have tried to disentangle the relative influences of genes and environment on creativity. Although it has been shown that there were modest genetic influences and substantial environmental effects on creativity, the specific genes and environmental factors that contribute to individual differences in creativity are still largely unknown. Recently, with the ongoing efforts of psychologists, it is delightful to see that great progresses have been achieved in identifying the specific genes and environmental factors that contribute to individual differences in creativity. To identify the molecular genetic basis of creativity, several candidate gene studies have been conducted to investigate the associations between dopamine-related genes and creativity. Findings from these studies generally support the involvement of dopamine-related genes in creativity, and highlight the critical roles of the catechol-O-methyltransferase gene (COMT), the dopamine D2 receptor gene (DRD2), the dopamine D4 receptor gene (DRD4) and the dopamine transporter gene (DAT). As for environmental factors, previous studies have found that early family environment (e.g., parenting styles and socioeconomic status) plays an important role in creativity development. Moreover, since creativity is an emergenic trait that determined by the interaction of genes and environment, several studies have found evidence for the interactions of dopamine-related genes with family environment (e.g., parenting styles) on creativity, demonstrating that genes could be either risk or plasticity to modulate the effect of environment on creativity. Obviously, these findings provide important insights concerning how genes and environment may influence creativity; however, there is still a gap in mechanistic understanding of the molecular biological mechanisms by which environment and gene-environment interaction may influence creativity. Recently, with the development of epigenetic studies, identification of the epigenetic basis of complex traits and behaviors has been one of the leading issues in psychological research. Epigenetic studies focus on the non-genotoxic, reversible, heritable mechanisms that influence gene expression without changing the DNA sequence. Epigenetic process, such as DNA methylation, has emerged as a potential mechanism through which the genome can capture the effects of environment and propagate the influence. As a potential mediator between environment and genome, the epigenetic approach provides an opportunity to reveal how the complex interactions of genes, epigenetics and environment give rise to individual differences in creativity. Based on this notion, by investigating the relationship between methylation of dopamine-related genes, family environment and creativity, the present study aims to reveal the epigenetic basis of creativity and the molecular biological mechanisms by which environment and gene-environment interaction may influence creativity. To this purpose, a two-stage design was employed in the present study. Stage 1 is designed to systematically investigate the association between methylation of four dopamine-related genes (COMT, DAT, DRD2 and DRD4) and creativity, and aims to identify the gene whose methylation pattern is associated with creativity. Stage 2 focuses on the identified gene whose methylation pattern is associated with creativity, and is designed to investigate the relationship between family environment, genotypes, methylation and creativity. It is expected that findings of the present study would help to demonstrate the epigenetic basis of creativity and to provide important insight into the mechanisms by which genes and environment interplay with each other to influence creativity.

Key words: creativity, gene, environment, epigenetics, DNA methylation