Table 1.

Numbers of Males and Females in Populations of Unrelated Persistent Stutterers, and χ² Analysis of the Differences in Gender Ratios between Groups^[Note]

	No. of Patients in Population
Sex	HCRI Alumni	NSP Members	SFA Records	AIS Alumni	Total
Males	810	285	131	826	2052
Females	156	112	52	212	532

Note.—Overall, familial cases versus general stuttering population χ²=43; df 1; P<.00001. Familial cases versus cases ascertained via therapy programs χ²=63. P<.000001. Familial cases versus cases ascertained without respect to treatment χ²=13. P<.002.