Women are much more likely to be persuaded to either eat healthily or undertake dangerous dieting by other women, not men, according to new ANU research.

The research by PhD student Tegan Cruwys, released during National Psychology Week, found that both healthy, and unhealthy, messages delivered by men had little effect. Additionally, she found that when a healthy eating message is delivered by someone women identify with, it was likely to change their behaviour. The findings highlight the importance of carefully targeted health messages.

To conduct the research, Ms Cruwys, a PhD student in the ANU Department of Psychology, showed female participants four health promotion videos in an online experiment, with either a pro-health or pro-dangerous dieting message, delivered by either a male or a female.

“We found that the women who watched the videos with the woman speaking were far more persuaded by the message,” said Cruwys. “That is, women planned to engage in healthier behaviours after seeing a pro-health message from a woman, and less healthy behaviours after seeing a pro-dangerous dieting message from a woman.”

She added that the videos which were delivered by a male presenter had little effect on the female participants in the study.

“The videos with the male speaker had little impact. The effect was particularly pronounced for the measure of interest in healthy eating – 40 per cent of women who saw the pro-health message from a woman clicked a link to find out more information about healthy eating, while only eight per cent of women who heard the same message from a man did.

“A person’s identity is more than just their personality and preferences. It’s also important to consider group membership in predicting behaviour. We found that the more a woman saw her gender as a central part of her identity, the less her personal attitudes mattered. So even if she thought being thin was desirable, a woman who saw herself as a woman was more influenced by the female’s message than her individual beliefs,” she said.

“This research shows that social influence can be a powerful predictor of behaviour, and that even something as simple as a seven-minute health promotion video can lead to big differences in people’s behaviours.”

A video interview with Tegan Cruwys featuring excerpts from the health promotion videos is available on ANUchannel at YouTube