Table II.

Number of times that the female and male displayed the same behavior (summed over all 8 pairs), the expected frequencies under the hypothesis of independent behavior, and the differences between the observed and expected frequencies

Time interval	Observed	Expected	Difference
18–19	188	160	28
19–20	434	338	96
20–21	433	380	53
21–22	452	438	14
22–23	394	352	42
23–24	311	288	23
24–	367	346	21