Humans of the last 10,000+ years share almost identical minds and bodies, differing only by their surroundings. If you and a caveman baby switched places at birth, I believe you would integrate into the caveman family just like any caveman baby, and the caveman baby would integrate into modern society just like any modern baby. The caveman baby would grow up accustomed to airplanes, cars, electricity, and computers, while you would spend the day hunter-gathering and salivating at the thought of raw vegetables. Much of a population’s lifestyle is determined by surrounding conditions, which change dramatically more quickly than human DNA.
When studying people from the past, you can empathize and connect more deeply by keeping in mind they are fundamentally the same as you, only existing in different circumstances. It is important to remember they were humans just like us when reading about them in textbooks. For example, commoners in a Middle Age fiefdom never left the few-mile radius around their settlement for their entire lives. Even though today I would be driven crazy not exploring the outside world, that would be the life I was accustomed to. Although difficult, I can imagine waking up in their smelly shoes.