Table 1.

Summary statistics for time to solve the puzzle

	Patrilineal	Matrilineal	Total
Female
Mean	57.2	35.4	42.6
Median	42	20	33
SD	55.8	20.1	37.4
n	218	443	661
Male
Mean	42.3	32.1	36.2
Median	32.5	27	29
SD	37.3	19.2	28.4
n	250	368	618
Total
Mean	49.2	33.9	39.5
Median	37	28	30
SD	47.4	19.7	33.5
N	468	811	1,279

Subjects solved a four-piece jigsaw puzzle. The time, in seconds, that it took to complete the puzzle acted as our measure of spatial ability.