RE: 29.5 Minimum age, not the gap?
Can you clarify what you mean by minimum age? Minimum age for what exactly?
Minimum socially acceptable age.
If you are 26, you should not be involved with those under 20 years of age to avoid the cringe factor.
If you are 36, it would look bad to be with someone under 25.
And if you are 76, below 45 is where you look like a creeper.