SCIENCE: Sex Differences in Furniture Assembly Performance: An Experimental Study. “Our results showed that men assembled the furniture faster (d = 0.78) and more accurately (d = 0.65) than women. Overall, participants performed better with step-by-step instructions than without (d = 0.61), and the time spent on instructions was negatively related to MRT scores, r = −.428, p = .006. Aside from the time spent on instructions, women assembled the furniture nearly as fast as men did, and the sex difference in assembly score could be explained by differences in individual spatial ability.”