48/27
I’m shocked that it didn’t say six, which is what my husband always teased me about being. Hey, there’s nothing wrong with parades and amusement parks and fireworks and bugs and mismatched socks and finger painting…
Real 54. Mental 29. And that includes being a coffee orderer after meals. I figured that one would boost me up a bit.
I figured 17 also but ended up with 16. I wasn’t trying for a low score, I was honest, it really does take effort for me to act like an adult.
How could it not be? 
My mental age is 15 even though I said a pension was essential.
Real 64, mental 34. But the test is so old that I’m not sure of the responses. Miley Cyrus was considerably less over when the test was written.
Happy with my score - but I age slowly.
Chronologically I’m 33.
Mentally I’m 55.
I mean, they pretty much nailed it. I’ve felt about 55 for my entire life, and currently many of my friends are thereabouts.
Dunno what I think about that test.
Chronological age: 86
Mental age 27:
???
Some of the answers had a sort of UK slant to them. An “Ice Lolly”?
Real Age 26. Mental Age 55
Real age: 76
Mental age: 34
My father always said I was immature.
Real age: 21
Mental age: 44?
I guess I’m older than I appear. Another test on this link stated my mental age as 52. (Sophisticated)
Is it wrong to have an older mental age? But I guess I’d do the same thing Clint Eastwood would do if he found intruders near his lawn (sans the shotgun, of course- I prefer tasers.)
Actual age: 41, mentally: 33.
Neat, I expected to be in the grandpa category.
Real: 46
Mental: 48
I really childish, but the questions brought the grown man in me.
Actual - 59
Mental - 46
Biological - 51( http://www.biological-age.com/)
I think I’ll go with the 46.
Real age = 21
Mental age = 48 (after a re-test)
Biological age - 11?!
I think that “Biological age test” is broken once you claim your birth year is 1994. (It is for me).
Real age=57
Mental age=33
I knew I liked you. My real age is 67/ mental 40.
Real age 46, mental age 41. That’s just about right. (Good thing I just visited the UK a month ago; otherwise, a few of the questions would have been a bit difficult to understand. “Ice lolly”??)
ETA: Brodi noticed the same thing, a month ago.
Many of us middle-aged-or-older Dopers use FB, too*. Not so much other two thingamajigs you mentioned.
*I’ve even posted to the SDMB FB page – hybrid technology! 
Real age 48, mental 37. No surprise, kind of expected it to be younger, and I can’t say that I’ve changed much since I was 37. OTOH, I’m sometimes as silly as an 8 year old and sometimes grumpy as an octogenarian, so all in all the real mental age seems to be more like the median of those characteristics which a test like this cannot capture. But hey, it’s a fun test.