A fascinating subject, and one I often ponder these days.
DH is from a solid scientific background - father was an engineer, mother trained (but never qualified, due to early marriage/dc) as a nurse. Both DH and his sister studied maths or related subjects at Oxford.
Both my parents left school before taking any qualifications BUT my dad joined the navy and rose to a high rank because he was such a brilliant engineer. My mum's dad won a scholarship to study maths at Oxford shortly before WW2 but was never able to take it up, due to poverty/family commitments. My mother eventually became an accountant.
So you'd think I'd be good at maths? No. Both my brother and I are relatively crap. I was in top sets at school until I was 12, then we moved house and the curriculum at the new school was completely different. The mental shift required to go from a very traditional syllabus to SMP (which I still think of as 'modern maths') defeated me. Perhaps it bored me. I don't know but, from then on, I clung to my strengths in arts and humanities.
Dd1 (Y4) is a talented writer and in top set maths, but not terribly interested in it. Dd2 (Y3) is bloody brilliant at maths, in line with her heritage. I try very hard not to let dd1 coast along on the strength of her literacy skills, but she seems to have set her face against maths already. I'd love her to learn to love it, but it's not really my thing and I'm afraid she's already decided she's 'Literacy DD' and her sister is 'Numeracy DD'.
(Obviously I do nothing to encourage this...or, at least, I try...)