London, Feb 19 (IANS): Stress can make people with high level of anxiety poorer by denting their confidence to compete, suggests a new study.

The findings suggest that stress can even be a cause of social inequality rather than just a consequence of it.

Two major factors -- stress and the person's general anxiety -- influence people's confidence, explained researchers Carmen Sandi from the Swiss Federal Institute of Technology in Lausanne (EPFL) and Lorenz Goette from the University of Lausanne in Switzerland.

Technically, anxiety is referred to as "trait anxiety", and it describes how prone a person is to see the world as threatening and worrisome.

Stress can actually boost the competing confidence of people with low trait anxiety, but significantly reduce it in people with high trait anxiety, the findings showed.

For the study, the scientists designed a behavioural experiment, which began with more than two hundred people taking two online tests: one to assess their IQ, and one to measure their trait anxiety.

All participants, stressed and non-stressed, were then given two options in a game where they could win money: they could either take their chances in a lottery, or they could use their IQ score to compete with that of another, unknown participant's -- the one with the higher IQ score would be the winner.

In the non-stressed, control group, nearly 60 percent of participants chose the IQ score competition over the lottery, showing overall high confidence in the participants, regardless of their trait anxiety scores.

But in the group that experienced stress before the money game, things were different. The competitive confidence of participants varied depending on their trait anxiety scores.

In people with very low anxiety, stress actually increased their competitive confidence compared to their unstressed counterparts while in highly anxious individuals, it dropped.

Stress, it seems, can raise or suppress an individual's confidence depending on their predisposition to anxiety.

The study was published in the journal Psychoneuroendocrinology.