Thinking about mating can significantly influence people's decisions about spending and giving, researchers have revealed.
A study led by Vladas Griskevicius from Arizona State University in Tempe and Josh Tybur from the University of New Mexico in Albuquerque invited college students to the lab in small groups. Each was randomly assigned to one of two conditions: "mating" or "non-mating".
The findings revealed that men in the mating condition said they would spend much more money on luxuries than men in the non-mating condition.
For instance, they might take the European vacation rather than saving that money, however, women remained unaffected.
In contrast, women in the mating condition said they would spend more time on conspicuous pro-social volunteering.
This study confirmed that conspicuous consumption (for men) and conspicuous charity (for women) could be increased by thinking about mating opportunities.
The researchers have called it "costly signalling theory," reports New Scientist.
In another study, college students were given a choice to spend money on conspicuous consumption or on more generous forms such as donating to natural disaster victims at an on-campus booth or spend time on more heroic activities such as saving someone from a burning building or distracting a grizzly bear from attacking a stranger.
The researchers found that both mating-primed women and mating-primed men said they would spend more on generosity-signalling conspicuous spending.
Also, mating-primed men said they would do more heroic helping, but not more non-heroic helping.
The study also showed that men who were most interested in promiscuous, short-term sexual liaisons showed the largest increase after the mating priming in both generosity-signalling conspicuous spending and in heroic benevolence.
This is strong evidence that men use these behaviours as costly mating signals.
Researchers also found that both sexes showed a marginally higher interest in socially prestigious pro-social behaviours when they were mating-primed, like volunteering with Hollywood celebrities in the Make a Wish Foundation for terminally ill children.
However, only the mating-primed men showed a higher interest in the socially dominant pro-social behaviours, and this effect was prominent in highly promiscuous men.
Another study led by Jill Sundie from the University of Houston, Texas, Griskevicius showed that high-promiscuity men were more willing to borrow fashionable clothes from a friend to impress a potential mate.
Mating primed men said they would spend more money on items such as designer sunglasses or an elaborate car stereo rather than inconspicuous products such as low-cost jeans or a toaster.
Women rated a man driving a Porsche Boxster as more attractive for a short-term sexual relationship than a man driving a Honda Civic.
Evolutionary psychologists Martin Daly and the late Margo Wilson from McMaster University in Hamilton, Ontario, Canada, also showed that mating priming influences economic behaviour more strongly among males than females.
Men who saw attractive women became much more motivated to get whatever money they could in the short term, presumably so they could spend it on conspicuous consumption to attract mates.
The findings were published in Journal of Personality and Social Psychology.