Table 1.

Twin Correlations with 95% confidence intervals

	MZM	DZM	MZF	DZF	DZOS
Cross-twin within trait correlations
Paranoia	.47 (.41-.52)	.28 (.20-.34)	.55 (.51-.59)	.30 (.23-.35)	.24 (.19-.28)
Hallucinations	.37 (.30-.43)	.27 (.20-.34)	.48 (.43-.53)	.33 (.27-.39)	.23 (.18-.28)
Cognitive disorganisation	.40 (.34-.46)	.30 (.23-.37)	.50 (.45-.54)	.20 (.13-.26)	.24 (.19-.28)
Grandiosity	.48 (.42-.53)	.23 (.16-.30)	.49 (.45-.54)	.31 (.25-.37)	.24 (.19-.29)
Anhedonia	.47 (.41-.53)	.23 (.16-.30)	.49 (.44-.53)	.26 (.20-.32)	.19 (.14-.24)
Negative symptoms	.83 (.80-.85)	.53 (.47-.58)	.83 (.81-.85)	.59 (.55-.63)	.50 (.46-.54)
Cross-twin cross trait correlations
Paranoia-hallucinations	.24 (.17-.31)	.13 (.05-.20)	.31 (.25-.36)	.19 (.17.25)	.15 (.10-.20)
Paranoia-cognitive disorganisation	.24 (.17-.31)	.17 (.09-.24)	.32 (.26-.37)	.18 (.11-.24)	.15 (.10-.20)
Hallucinations-cog disorganisation	.20 (.13-.27)	.25 (.17-.32)	.33 (.27-.38)	.22 (.16-.28)	.15 (.10-.20)
Cognitive disorganisation-negative symptoms	.23 (.16-.30)	.19 (.11-.26)	.22 (.16-.28)	.20 (.14-.26)	.15 (.10-.20)

Note: MZM=monozygotic males, DZM=Dizygotic males, MZF=monozygotic females, DZF=dizygotic females, DZOS=dizygotic opposite sex. Self-report data was available for 1400 MZ males, 1319 DZ males, 1995 MZ females, 1770 DZ females, 2998 DZ opposite-sex twin pairs. Parent-report data was available for 1410 MZ males, 1322 DZ males, 1994 MZ females, 1760 DZ females, 3024 DZ opposite-sex twin pairs