Forensic portraits

Just musing...

If you had the photograph (or charcoal likeness, etc.) of your great-
grandmother and of two or three of her children, could a forensic
portraitist draw a portrait of your great-grandfather? with a
probability that +/- some percentage (say 10%), the likeness was a
good one? [or, as the pollsters put it, 19 times out of 20, that the
likeness you'd get is about 90% right, haha.]

CWatters...

No chance. For one thing you can't tell what percentage they inherit from
their mother or father. An old school friend that I haven't seen for 20
years recently sent me photos of his children. One looks exactly like him
and the other looks nothing like him. However, if you had a few photos and
wanted to know which was most likely to be the father then they might be
able to give you an idea. I think it would depend on luck as much as
anything.

... or a series of portraits representing a probable range of
likenesses?

I suppose the probability of obtaining a reasonable likeness goes up
when you have more portraits of other relatives, say, siblings of
your great-grandfather. Even pictures of your great-grandmother's
siblings might assist to isolate her family's features from her
husband's.

Or is this all just a pipe dream?

John...

yes Alison !!!