You’ve heard it all before: “happy cows produce more milk,” free-range and grass-fed meat tastes better. But, is it true?

According to a new study, a person’s beliefs on how a farm animal was raised can actually define their meat-eating experience — despite whether it was actually raised on “factory farms” or in more humane conditions.

"We show that what you feel very directly influences not only how you interpret what you see but also very literally what you see," said Lisa Feldman Barrett, a pioneer in the psychology of emotion and the director of Northeastern's Interdisciplinary Affective Science Laboratory. "We call this 'affective realism' — the tendency of your feelings to influence the actual content of your perceptual experience." The findings, she said, suggest that anyone interested in creating things, from a chef to a filmmaker to a designer, "should consider how beliefs influence the user experience."

Barrett, co-author Eric Anderson and researchers conducted the study by pairing identical meat samples with different descriptions — either raised on factory farms or a more natural environment. Additionally, a control group had no label. From there, participants' eating experiences were reported. Results showed that where people thought that the meat was raised affected their perception of its look, smell and taste.

Study participants sampled beef jerky, roast beef and thick-cut ham in three separate experiments. In every case, the “factory farmed” meat got worse ratings from tasters; participants even thought it tasted saltier, greasier, and staler.

"We were largely hypothesizing that labeling something as raised on a humane farm would improve taste and appearance and other characteristics of the meat sample," Barrett said. "But what we found instead is that explicitly labeling something as factory farmed harms the perceptual qualities of the food."

These findings align with an emerging body of research which shows that our beliefs can influence how we evaluate food.

Source: Anderson EC, Barrett LF. Affective Beliefs Influence the Experience of Eating Meat. PLOS ONE. 2016.

Read more:

Vegetarian Diet Benefits: What Happens When You Quit Eating Meat?

Eating Red Meat Linked To Kidney Failure Risk