First impressions always come with certain assumptions about someone’s personal life—their age, career, hobbies and personality. Whether that’s a good or a bad thing, it’s natural. These assumptions also frequently include guesses about someone’s relationships and what their family makeup is. Maybe you’re introduced to a couple, and because of their age, gender or appearance, you assume that they’re married with kids. Or you meet a young woman with a child, and because of her age, you assume that she must be a sister or babysitter, not the child’s parent...