Hans and Sybil Eysenck. Direct answer:

• Hans Eysenck and his wife Sybil Eysenck were prominent psychologists who argued that personality traits are substantially influenced by genetic inheritance. Their biologically based theories posited that underlying physiological systems, which are heritable, shape dimensions of personality such as extraversion and neuroticism. This view is commonly summarized as a genetic contribution to individual differences in personality, though contemporary research emphasizes a complex interplay of genes and environment.