Regarding the misattributed paternity numbers/rates:
Obviously interviewing people isn't going to reveal the correct numbers: If a mother isn't going to tell her child, or doesn't know [switched in the maternity ward, chimera, multiple partners] chances are they aren't going to tell some random researcher either.
However, there was some interesting research at a hospital in the UK (maybe Bristol ?) which tested the men which were present at the birth of the child against the child, and the numbers are rather high - something above 1 in 20. And this is for the men that were present.
There is every reason to believe that this is strongly influenced by culture.
Perhaps the Swedish have a higher incidence, and the Saudis lower. One should not look at a single study in a single place at a single time, that depends almost entirely on human behaviour, and extrapolate to humans as a whole.
The actual rate of non-paternity in western societies is closer to 3%. The 10-20% figures that appear regularly on the internet are largely derived from rates of non-paternity in cases were paternity was questioned (i.e. pre-existing suspicions of infidelity). The higher ranges quoted (30% is the highest I have seen) are generally from small study populations with extended periods of partner absence, like central American itinerant laborers or African truck drivers.
Obviously interviewing people isn't going to reveal the correct numbers: If a mother isn't going to tell her child, or doesn't know [switched in the maternity ward, chimera, multiple partners] chances are they aren't going to tell some random researcher either.
However, there was some interesting research at a hospital in the UK (maybe Bristol ?) which tested the men which were present at the birth of the child against the child, and the numbers are rather high - something above 1 in 20. And this is for the men that were present.
Something which should be more common knowledge.