It's deffo 4 for me. I can see 4 in one shot, if it's say 5 or 6 or a bit higher I have to split the group and subitise each then sum them. YMMV and your mileage beats mine :)
Huh. Interesting. I thought it was one of those things like how we ended up with base 10 numbers because we have 5x2 fingers and that kinda stuff, but interesting to know I was off.