Probably several reasons for this. It could be that this step was inadvertently omitted at the time the info for the profile was set up or omitted on purpose for privacy reasons. Except for the screen name and sex all of the settings on the profile can be edited at any time. Of course, it is helpful to list the age, marital status, along with the country and city of residence if a single member is interested in attracting someone for a prospective relationship.