The GENDER statement specifies a variable that indicates the sex of the individuals. Values of the sex variable must be character beginning with ‘M’ or ‘F’, for male or female. The GENDER statement is needed only when you specify the AVERAGE option to average the inbreeding/covariance coefficients within sex categories or when you want to include a gender variable in the OUTCOV= data set.
PROC INBREED makes the following assumptions regarding the gender of individuals:
The first parent is always assumed to be the male. See the section VAR Statement.
The second parent is always assumed to be the female. See the section VAR Statement.
If the gender of an individual is missing or invalid, this individual is assumed to be a female unless the population is overlapping and this individual appears as the first parent in a later observation.
Any contradictions to these rules are reported in the SAS log.