In Japan (and probably several other cultures), it's common to list your birth order in your dating profile. This is because if you're the first born you're exp

In Japan (and probably several other cultures), it's common to list your birth order in your dating profile. This is because if you're the first born you're expected to take care of the parents and many people choose to explicitly NOT date such people, especially women, since they'll likely be tasked with taking care of the 1st born son's parents.