Back on topic, if scientists were to clone a Neanderthal using a borrowed modern human egg containing maternal mitochondrial DNA, subtracting the human DNA from the nucleus, and then adding nuclear DNA from a Neanderthal man, then that cloned entity would not be truly a Neanderthal man because the maternal mitochondrial DNA would be from a modern human. Neanderthals had different maternal mitochondrial DNA, which means that their energy levels might have been different from that of modern man. Besides the mitochondrial DNA, what other organelles inside the human cell might be different from that of Neanderthals? Would this add to their quality of life or subtract from it? Ethically, it would be a can of worms to conduct such an experiment. And no doubt, with scientists involved, religion prpbably would not factor into the equation and these Neanderthals might be treated more like chimps than humans, and more like property or slaves than humans.
I wonder what the Neanderthals were like personality wise? Were they as competitive as we humans are? Or were they more competitive and territorial?
I'll defer to science on these matters.
With their temperaments could they even be Christians? This is a serious statement. I used to have a book written by a Roman Catholic priest which discussed the catechumenate. He said that the Roman Catholic Church has for centuries tried to convert gypsies, but has had very little success due to their cultural values or lack of moral values.
Could temperament be a hindrance to Christian baptism?
I suspect the RC's have had very little success with gypsies not because they naturally present impediments to conversion, but because they are in some way resistant to accepting it. In other words, it's not that gypsies are, by their very human constitution, incapable of becoming Christians, but perhaps their culture and way of life are so entrenched that they are unable to conceive of accepting the gospel. And it might not even be that at all: it's not like the Christians the gypsies are regularly encountering are stellar exemplars of the gospel. If they are OK with their lives, and some "Christian" shows up telling them how they should convert, and that Christian is more or less lousy, that could also prevent them (it prevented Gandhi, after all). As with science, I'm no expert on gypsies, so I'm just throwing out a couple of suggestions.
I don't know what you mean by "temperament" in order to say whether or not it could be a hindrance to baptism. If your temperament is "hostility to Christianity", then I suppose it would be an impediment. If, however, it is "Do I really have to get baptised wearing only shorts in a kiddie pool in front of all those people?", I suppose that is a different matter.
Is that why from the time of Adam until Christ was born there were many generations of men so that man under the guidance of the Holy Spirit might be made more receptive to Christianity?
I suppose you could put it that way. St Paul speaks of how Christ was born of a woman and born under the law "in the fullness of time". There is a line of thought, either in the liturgical texts or in some patristic writings (perhaps both, and I apologise that I don't have citations handy), that the progression of generations was to allow mankind to produce the Virgin Mary so that she could become the Mother of God. In the process, one can observe in the various world religions, literature, cultures, etc. elements that, on their own, may not look like much, but in light of Christ we see how they were pointers or indicators the meaning of which would become clear once the gospel was preached to them, enabling the nations to accept it more easily (St Justin speaks of something like this).