Midwives have been told about the benefits of “close relative marriage” in training documents that minimise the risks to couples’ children.
The documents claim “85 to 90 per cent of cousin couples do not have affected children” and warn staff that “close relative marriage is often stigmatised in England”, adding claims that “the associated genetic risks have been exaggerated”.
That’s because like NHS in this case, X-COM *lies *.
It lies in your favor, though. On difficulties below the highest, there are hidden modifiers that affect the hit chance that you can’t see, but all of them are cheating for you. IIRC your hit chance secretly increases when you have missed shots recently, when you have dead soldiers, when you are outnumbered, and maybe some other things.