Do we inherit anxiety through our genes, or learn it from those closest to us? ‘Nature or nurture?’ looks at the evidence. Twin adoption studies point to a genetic influence, but researchers have failed to find a single gene responsible for anxiety, suggesting that a complex interaction of genes and environment causes anxiety. The polygenic theory indicates that several genes are involved in the generation and maintenance of anxiety. Genes are responsible for 40% of heritability and a tendency towards a high level of anxiety rather than a specific disorder. Research into childhood experiences — focussing on trauma, parenting, and learning from others — considers the likelihood of developing anxiety disorders.