Hi there! I'm a Peds/Psych intern (not like a Child psychiatrist, but more like med/peds in that my residency is in both fields). I've spent about 6 months with each group now, so I think that gives me a bit of perspective just cuz they are very different worlds.
While it is true that Peds and all specialties attract all kinds of people, Peds (and Psych, for that matter) has its own little "corporate culture" that tends to be overarching.
On the plus side, I've found pediatrics residents and attendings to generally be kind, understanding, and caring sorts. It is rare that you will meet an overtly malignant person who seeks to be intimidating. Pediatric folk do seem to be more interested in the psychosocial aspects of the patient and also in family dynamics (since all kids live in a family of some stripe or fasion). This could be good or bad for you, depending on where you interests lie.
On the down side, I do find that when peds people don't like the way you do something or disagree with your methods, they have a tendency to be passive-aggressive and gossip about it, rather than just letting you know. In addition, I take issue with their extremely regimented ideas about child-rearing issues. I was out of a car seat by age 4, was bottle-fed, and got chickenpox. And I did just fine. But you'd better believe in booster car seats for third graders, rotavirus vaccines (god forbid kids get diarrhea!), and that formula is the devil. If you don't really think these things are that crucial, you'd just better pretend and start goose-stepping like the rest of them. As a touchy-feely psych person, I'd rather let the family raise kids the way they see fit (within reason of course!) and work more on building a long-term therapeutic alliance than force-breastfeeding every infant. But such is the thought process in peds...do what we say, or you're not a good parent (We call this "anticipatory guidance").
For what it's worth, all specialties have their downsides, and I've found my time on psych to be rewarding but also punishing in all the opposite ways. In psychiatry, there are no right answers....anything goes. Peds is almost the opposite. I'm looking to hopefully work towards a happy medium years from now when I'm in my own Peds/Psych practice. I know I've rambled on, but I do think your concerns are valid, the whole "do i fit in to the culture and values of this specialty?" question is just as valid as whether or not you like the subject matter. Just my 2 cents. Best of luck 🙂