What a great article, Gratiela.
I have three sons and one daughter, and they were all completely different.
My second youngest son was by far the most sensitive and reactive to all around him.
My oldest son intelligent, reckless and confident, my daughter quite but also very independent and has no filters - she says exactly what she thinks.
My youngest son often suppressed his feelings but gets on well with every one and rarely gets stressed about anything.
Overall, I would agree with your findings, that boys tend to be more sensitive in many cases.