Aston University research shows seeing someone dislike vegetables can make observers dislike them too

New research carried out at Aston University shows that observing facial expressions of others eating raw broccoli can influence people’s liking of the vegetable.

Dr Katie Edwards in the School of Psychology led a team investigating if observing the facial expressions of others while they eat raw broccoli encouraged or discouraged an observer from liking or wanting the same vegetable. They found that if someone eating raw broccoli had a negative facial expression, this resulted in a reduction in the observers’ liking of it.

Humans learn which behaviours pay off and which do not from watching others and draw conclusions about how to act, or eat. In the case of the latter, people may use each other as guides to determine what and how much to eat. This is called social modelling and is one of the most powerful social influences on eating behaviour.

Dr Edwards said:

“We show that watching others eating a raw vegetable with a negative facial expression reduces adult women’s liking of that vegetable, but not their desire to eat it. This highlights the power of observing food dislike on adults’ eating behaviour.”

In the study, just over 200 women watched a video containing clips of different unfamiliar adults consuming raw broccoli. While eating, the models displayed positive (smiling), neutral, or negative (disgust-like) facial expressions. The researchers examined only women’s reactions since gender differences may exist within the modelling of eating behaviour, and modelling effects can be different among women and men.

Previous research shows that behaviours are more likely to be imitated if positive consequences are observed, and less likely to be imitated if negative outcomes are witnessed. In the present study, however, this effect was observed only partially. Exposure to models eating broccoli while conveying negative facial expressions resulted in a greater reduction in liking ratings, whereas the reverse did not hold. Watching someone seemingly enjoying the raw broccoli did not increase adults’ vegetable liking or eating desire.

One possible explanation may be that avoiding any food that appears disgusting – irrespective of whether it is commonly liked or disliked – can protect us from eating something that tastes bad or is harmful. Another reason may be that smiling while eating is perceived as an untypical display of liking a certain food.

Edwards said that watching someone eating a raw vegetable with positive facial expressions does not seem to be an effective strategy for increasing adults’ vegetable consumption.

There is still much that needs to be understood about the interplay of obvious enjoyment and the liking of food. The researchers have focused on adults, and while this has not been tested for on this occasion, they said that the findings about the influence of negative facial expressions could apply to children, because children tend to be less willing to try vegetables by default. Previous research has shown that positive facial expressions increase children’s vegetable consumption.

Edwards said:

“For example, if a child sees their parent showing disgust whilst eating vegetables, this could have negative consequences on children’s vegetable acceptance.”

In the present study, participants also watched short video clips, rather than watching people eat in front of them. This allowed them to observe the dynamic nature of reactive facial expressions, which is more realistic than looking at static pictures; however, in the future, an important focus will be to examine the effect of watching live food enjoyment on eating behaviour, the researchers said. More research is also needed to see whether the findings from this study translate to adults’ actual intake of vegetables.