A not-very-scientific perspective from the gay community. Once I started going online, it quickly became obvious that truth in advertising was not a common value. One guy I met was easily 20 years older than what his profile stated. I took an informal survey of friends who were working the apps and found that the average number of years shaved off was seven (the sample size was too small to be meaningful, but it did confirm what I had come to suspect: virtually everyone lied about their age).

It is worth noting that the gay "dating" apps are primarily used by guys looking for a quick roll across the mattress. They feel that they can fudge it a bit because this is a one night stand and their partner will never know. They also feel that they MUST shave a few years off because the gay community is notoriously agist. If someone truly wants a LTR, this is probably not their best venue. I am not sure how the straight sites compare in those respects..