All kids are different, but FWIW, my daughter used to take our her pacifier and stick it in her twin brother's mouth when he was crying. When she was a bit older (maybe three?) she'd often give him the last strawberry or whatever from her plate if he finished first. She's five now, and she's an extremely generous and high empathy kid.
Maybe that's unusual, and on average kids can be selfish (or maybe self-centered), but it's not as black and white as you're describing.
Maybe that's unusual, and on average kids can be selfish (or maybe self-centered), but it's not as black and white as you're describing.