I've known a few people who are the same as your DD in liking to know how people tick and why they do things and they have said much the same as her about it being dry and tedious. I am very out of date but don't think the degrees will have changed hugely. They do go into more detail but it's kind of the same in greater depth. You have many many names and dates to remember as any argument has to be backed up.
Then there is the practical work plus stats and lots of drilling about hypotheses, abstract, methodology etc. Some courses are more science based than others but if the neuroscience caught her eye I guess that is something she'll be fine with. We used to share neurophysiology lectures with some of the medics and they were quite intense.
Cognitive psychology is the one that a fair few people on my course didn't enjoy much. . Things I personally didn't enjoy much was the visual perception and cognitive stuff but the health, social, criminal psychology plus sociology floated my boat.