Numerous studies have shown that severe early life stress can cause long term cognitive and learning impairments (ex. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3050094/)
But I have not found any studies that look into circumcision and cognitive outcome. The only study I've found is this recent German study: http://www.nature.com/tp/journal/v7/n3/full/tp201723a.html
Some tell me there are methodological flaws (such as small sample size and ineffective means to measure stress-related disorders). I personally can't spot any problems, but I'm not a neuroscientist.
What do you guys think in regards to this? Can an acute but severe bout of stress to a neonate cause any permanent neurological changes and cognitive impairments?