Corporal punishment = long-term negative effects

It is congruent with the proposals that creating low-anxiety, inclusive learning environments produces better learning. Write up is here: Corporal punishment may have long-term negative effects on children's intelligence: "Children in a school that uses corporal punishment performed significantly worse in tasks involving 'executive functioning' -- psychological processes such as planning, abstract thinking, and delaying gratification -- than those in a school relying on milder disciplinary measures such as time-outs,"
I wonder whether this has some bearing on learning outcomes for different communities in Britain. There are some distinct educational outcome differences between different cultural communities inhabiting the same socio-economic spaces in cities in on instance I know of, the attendance of male children at after school classes where corporal punishment is often part of the the environment, is not only getting in the way of their being able to do the homework and be rested for the next day's work, but may be creating a higher anxiety response to classroom/learning situations. The further danger is this:

These results are consistent with research findings that punitive discipline may make children immediately compliant -- but may reduce the likelihood that they will internalize rules and standards. That, in turn, may result in lower self-control as children get older. ... corporal punishment does not teach children how to behave or improve their learning. In the short term, it may not have any negative effects; but if relied upon over time it does not support children's problem-solving skills, or their abilities to inhibit inappropriate behaviour or to learn