Anxiety issues may begin in the womb, with babies deprived of certain hormones at greater risk of developing the trait in later life.
Insulin-like growth factor-2 has been shown to play a major role in fetal and placental development in mammals, and changes in expression of the hormone have been implicated in growth restriction in the womb.
Although these studies were carried out in mice, the findings may have wider implications for human development, according to the researchers.
Read more at Cardiff University