Harsh parenting could be display of anger, threats and even spanking. The study found that women who carry this gene have a tendency to become violent, hit or shout at their children. Mutation of this gene had a control over mood, scientists said.
The gene known as DRD2 controls dopamine which regulates behavior and mood in the brain.
Dr Dohoon Lee, of New York University, said: 'It's commonly thought economic hardship within families leads to stress which - in turn - leads to deterioration of parenting quality. But these findings show an economic downturn in the larger community can adversely affect parenting - regardless of the conditions individual families face.'
Dismal financial situation did not seem have an adverse effect on the parenting style of mothers who did not possess this sensitive gene.
Professor Sara McLanahan, of Princeton University, said: 'People can adjust to difficult circumstances once they know what to expect - whereas fear or uncertainty about the future is more difficult to deal with.'