Table 2.
Total number of crossovers (mean ± SEM) during the 10-minute social interaction test for Experiment 2.
| Experiment 2 | |||||
|---|---|---|---|---|---|
| Age of Experiment Animal (Months) | |||||
| Test Day | Sex | 3 | 9 | 18 | 24 |
| Novel 1 | Males | 12.10 ± 2.47 | 13.83 ± 2.81^ | 4.50 ± 1.40^$ | 3.22 ± 0.88^$ |
| Females | 16.78 ± 1.20 | 20.10 ± 2.23^ | 6.50 ± 1.18^$ | 4.78 ± 0.91^$ | |
| Familiar | Males | 12.20 ± 2.52 | 15.67 ± 4.14^ | 4.20 ± 1.35^$ | 3.11 ± 1.22^$ |
| Females | 14.44 ± 1.20 | 18.80 ± 2.94^ | 4.90 ± 1.17^$ | 3.11 ± 0.73^$ | |
| Novel 2 | Males | 8.90 ± 1.77* | 15.50 ± 3.17*^ | 3.40 ± 1.27*^$ | 1.89 ± 0.56*^$ |
| Females | 17.44 ± 1.75 | 18.30 ± 1.97^ | 5.90 ± 1.15^$ | 3.22 ± 0.88^$ | |
*
indicates a main effect of sex,
^
indicates a significant difference from 3-month-olds.
$
indicates a significant difference from 9-month-olds. Females exhibited more crossovers compared to males at all ages. Regardless of sex, 3- and 9-month-olds had more crossovers 18- and 24-month olds had fewer crossovers, whereas 18- and 24-month olds were not different from one another.