No, the birthday problem still works if you consider that the probability of being born on a particular day is uniform.

It's related to the fact that the probability of two people in a room having a birthday is more closely related to the number of pairs of people in the room (which in turn grows as O(n^2)), than to the number of people in the room.

A detailed proof/explanation can be looked up easily with Google, if you have a bit of mathematical maturity.

For those who down voted me, you do not know your sample set or your test subjects. Go to the empirical data sources. Human behavior certainly affects the real probabilities. As of 2015 in the US [0], a person is more likely to be born in July, August or September. They're also more likely to be born during the middle of the work week rather than the weekends. Draw your own conclusions from the data.

[0] https://www.cdc.gov/nchs/data/nvsr/nvsr66/nvsr66_01_tables.p...

Your information is interesting, but your inference is incorrect.

The Birthday Paradox has absolutely nothing to do with procreation, and everything to do with statistical probability.

Probability is just a model in lieu of the actual data with many built-in assumptions. Probability is a shortcut finding, collecting or generating data. My point is, if you have the data or a very large faction thereof, use it. Don't guess using probabilities.

Right, but it's really not about birthdays at all.

It's specifically about coincidences in a randomly distributed set.

It just says "birthday" in the common name because that's a relatable, if imperfect, example.

The birthday problem still exists even assuming that everyone has an equal chance of being born on any day of the year. It's a phenomenon of the statistical likelihood that given a large enough group of people, the likelihood that any two will have the same birthday goes to almost certainty very rapidly.

Thats....not how that works. At all.

Is this true? Which months are considered "summer"? Northern Hemisphere or Southern or both? This can easily turn into a "40% of sick days are on Monday or Friday" type fallacy.