It's widely accepted that boys and girls are hard-wired to develop differently from birth. Girls have better verbal skills, self-motivation and are much more able to empathise with others, whilst boys are more competitive, have better spatial and technical skills which help with subjects such as maths or science.
The gender gap starts very early on. A recent government study found that five-year-old girls continue to lead the way in all the early learning goals, with 74.3% achieving the expected level of development compared to 58.6% of boys.
This trend continues throughout primary school, with girls continuing to outperform boys in verbal skills which has a knock on effect on both reading and writing.