A hamburger that's 90 percent fat-free sounds a lot better than one with 10 percent fat. And even when the choices are the same, humans are hard-wired to prefer the more positive option.

This is because of what's known as the “framing effect,” a principle that new research from Concordia has proved applies to mate selection, too.

The study — co-authored by Concordia marketing professor Gad Saad and Wilfrid Laurier University’s Tripat Gill, and published in the journal Evolution and Human Behavior — shows that when we choose a partner, the framing effect is even stronger in women than it is for men.

“When it comes to mate selection, women are more attuned to negatively framed information due to an evolutionary phenomenon called ‘parental investment theory,’” says Saad, who has done extensive research on the evolutionary and biological roots of consumer behavior.

“Choosing someone who might be a poor provider or an unloving father would have serious consequences for a woman and for her offspring. So we hypothesized that women would naturally be more leery of negatively framed information when evaluating a prospective mate.”

To prove this, Saad and Gill called on hundreds of young men and women to take part in their study.

Participants were given positively and negatively framed descriptions of potential partners. For example:

“Seven out of 10 people who know this person think that this person is kind.”
[positive frame]
versus
“Three out of 10 people who know this person think that this person is not kind.”
[negative frame]

The researchers tested the framing effect using six key attributes, two of which are more important to men and women respectively, and two that are considered as necessities by both sexes:

• Attractive body (more important to men)
• Attractive face (more important to men)
• Earning potential (more important to women)
• Ambition (more important to women)
• Kindness (equally important to both)
• Intelligence (equally important to both)

Participants evaluated both high-quality (e.g. seven out of 10 people think this person is kind) and low-quality (e.g. three out of 10 people think this person is kind) prospective mates for these attributes, in the context of a short-term fling or a long-term relationship.

More often than not, women said they were far less likely to date the potential mates described in the negatively framed descriptions — even though in each instance, they were being presented with exactly the same information as in the positively framed descriptions.

Women also proved more susceptible to framing effects in attributes like ambition and earning potential, while men responded more strongly to framing when physical attractiveness was described.

This research highlights how an evolutionary lens could help explain the biologicial origins of seemingly “irrational” decision-making biases like the framing effect.