Speed-dating for science In the next few days, the volunteers met face-to-face with the people in the pictures, during the speed-dating event.
People turned out to be pretty good at knowing who interested them based on photographs alone, the researchers found.
Thank your medial prefrontal cortex, a brain region now discovered to play a major role in romantic decision-making.
"We think it is especially involved in comparing options against a whole bunch of other options, or some sort of standard," Cooper said.
Like any typical speed-dating night, participants rotated around the room and chatted with one another for five minutes.
After this meet-and-greet, they filled out forms indicating whom they'd like to see again.
Marriages have hit a record post-war low, with only 653,740 tying the knot last year, according to recent government figures, while average marrying ages have increased to 31 for men and 29 for women.
• Rise of Japan's middle-aged virgins Rising childcare costs and economic instability combined with a decline in the number of young women have contributed to a falling fertility rate (dropping to a figure of 1.4 babies over the lifetime of the average woman, well below the "rate of replacement".) As a result, the government and private companies are investing in initiatives such as matchmaking parties to encourage younger generations to marry and have babies.