An interest is children’s development (or human development in general) is a must! Also being interested in people’s behaviour is important. If you have the interest then you just have to do a psychology degree and then a PhD looking at development.
Different universities require different A-level grades and sometimes specific subjects to get on to a psychology degree. It is a good idea to work hard at all your science subjects and maths because they all come in useful.
Hi @ailhep123 and @justiekeeling7
I think Tim has covered this well, and he’s the expert, but you don’t need all your A-Levels to be science to get in to Uni to do Psychology. I did Psychology and my A-Levels were Maths, Biology, English and Music. I thought about doing all the sciences and maths but decided I would need some other subjects to help me stay interested during my A-Levels and give me some variety. English was great and I’m really glad I did it, as it helped my writing skills, which is useful as a scientist as you need to write papers to explain your findings to other people.