I teach primary in an area of considerable deprivation where the norm is Pupil Premium / Free School Meals. Many parents work or study. Children live in social housing, hotels or privately rented accommodation (which is often crowded, unsafe and otherwise problematic).
Within this cohort of seemingly shared socioeconomic experience, we still see different groupings as described by PPs upthread; state of uniform and shoes, how quickly reading records fill up etc. We're in a city, with many museums, libraries, galleries, city farms, youth clubs and other venues open for free to the public or offering free or heavily discounted experiences and activities (cinemas, theatres, music and sports venues etc) and a cohort of children always seems to be accessing these, due to their parents signing up for email updates, reading the local authority primary school bulletin and generally putting themselves in the loop. Much of this is what is deemed 'cultural capital' but we're always mindful to include less 'culturally elitist' activities when we consider the range of CC our pupils access -attending church, mosque, gurdwara or temple, volunteering, community centre activities, home language tuition, cultural celebrations etc, all form part of an individual's cultural capital.
I'd say that, just like in more affluent or mixed areas, parental engagement in their child's learning ‐in and out of school- is what informs so many things, both socially and academically.