Table 5.

MZ (below the diagonal) and DZ twin correlations for the twin 1 and 2 samples

	MT1	OA1	AR1	NS1	MT2	OA2	AR2	NS2
MT1	1	0.38	0.38	0.50	0.42	0.31	0.3	0.39
OA1	0.34	1	0.49	0.72	0.26	0.47	0.4	0.57
AR1	0.24	0.46	1	0.65	0.28	0.34	0.63	0.46
NS1	0.36	0.7	0.56	1	0.37	0.49	0.46	0.67
MT2	0.59	0.43	0.33	0.45	1	0.43	0.35	0.46
OA2	0.28	0.66	0.48	0.68	0.44	1	0.49	0.72
AR2	0.21	0.45	0.85	0.57	0.32	0.52	1	0.54
NS2	0.33	0.67	0.52	0.86	0.51	0.73	0.57	1

The number after the abbreviation denotes the twin member. (e.g. MT1 scores of the twin 1 sample on the Mazes test, MT2 scores of his/her co twin on this test)

CT Calendar test, CC cube comparison test, WV wide range vocabulary test, SD surface development test, AR simple arithmetic test, FB form board, SV self-judging vocabulary test, PF paper folding test, OA object aperture test, IP identical pictures test, NS newcastle spatial test, SA spelling achievement test, MT Mazes Test