Table 2. Summary of Key Variables in Study 1 Grouped by Age.

Age	Males						Females
	Number	Symmetry	Simple RT	Simple RT-SD	Choice RT	Choice RT-SD	Number	Symmetry	Simple RT	Simple RT-SD	Choice RT	Choice RT-SD
Note. Symmetry is measured as a percentage. Zero indicates perfect symmetry. All RT variables are measured in milliseconds. RT = reaction time.
4–6	35	.90	426	148	1,088	313	47	.70	456	169	1,121	328
7–9	89	.70	380	107	803	186	134	.68	378	98	790	182
10–12	67	.63	317	84	609	123	88	.74	328	80	633	127
13–15	19	.64	304	63	565	122	18	.60	278	56	555	104
All	210	.71	361	103	768	184	287	.69	369	101	782	184