Table I.

Number of complete and incomplete twin pairs who completed a STPI assessment by age interval, zygosity, and rearing status.

	50–54		55–59		60–64		65–69		70–74		75–79		80–84
	●●	●○	●●	●○	●●	●○	●●	●○	●●	●○	●●	●○	●●	●○
Variable: STPI
1.MZ	53	24	68	26	76	42	82	70	73	76	41	74	17	56
2.DZ	93	71	106	82	128	112	160	137	128	183	86	142	28	123
1.MZT	18	12	24	15	24	23	29	37	34	33	20	32	8	25
2.MZA	35	12	44	11	52	19	53	33	39	43	21	42	9	31
3.DZT	57	42	66	49	71	68	77	81	56	100	38	77	11	70
4.DZA	36	29	40	33	57	44	83	56	72	83	48	65	17	53
Total	146	95	174	108	204	154	242	207	201	259	127	216	45	179
Variable: APQ
1.MZ	60	33	92	27	102	49	109	75	101	93	67	98	39	71
2.DZ	125	75	144	96	179	138	223	175	191	223	125	196	57	182
1.MZT	20	17	32	14	34	26	43	39	42	41	31	38	19	27
2.MZA	40	16	60	13	68	23	66	36	59	52	36	60	20	44
3.DZT	69	45	87	57	95	87	113	104	90	130	64	109	30	98
4.DZA	56	30	57	39	84	51	110	71	101	93	61	87	27	84
Total	185	108	236	123	281	187	332	250	292	316	192	294	96	253

Note: Single participants may be in multiple intervals; discrepancy between STPI and APQ is due extra APQ timepoints ●● = complete twin pair; ●○ = incomplete twin pair; STPI=State Trait subscale from the State Trait Personality Inventory; APQ= Anxiety Personality Questionnaire; MZ = Monozygotic twin pair; DZ = Dizygotic twin pair; MZT = Monozygotic pair raised together; MZA = Monozygotic pair raised apart; DZT = Dizygotic pair raised together; DZA = Dizygotic pair raised apart