Can rhythm be "learned", or are you born beside it?

Can folks can learn to improve their sense of rhythm, and if so, how can they can accomplish this? Also, what exactly govern how good or bad a person's rhythm is (i.e. a quantity of the brain)?

Examples:
My cousin has taken dance classes for a few years, on & sour, yet she says her rhythm is still poor, & she frequently messes up because her timing is sour. It's not like she lacks motivation. :) She loves music & dancing, & would love to enjoy more rhythm, but it just doesn't seem to be going on.

I also have a friend who cannot clap in time to music to release his life! Even when it's a song with a drastically noticeable and simple beat, and even when other folks are clapping properly around him, he merely can't clap with the music! He finds it embarrassing but unexplainable. :\

Any insights? Just curious! Thanks!
Answers:    I suggest it can be learned. I was a music primary in college, and I have studied music my total life. I remember when I struggled with it when I be a kid, but now I am good at it.
There is a study curve. Yes it is true some people are better at it than others, but everybody can learn rhythm to some level. They need to pass the erudition curve plateau and then it'll be easier.
First I like to read aloud, I like your question. I do not leap, I have tried to learn, but I guess its not surrounded by my heart. I get motivated when I watch the TV show "Do you expect you can dance" or something similar. I wish I could. I have tried. Now, my sister, can pick up merely about any step and do it. She has won 1or 2 bop contest. I guess it's in her heart. This is all I can bestow. yes u have to b born with rythm contained by order for it to be good no concern how many dance classes u pocket