Why Do Some Parents Favor One Child Over Another?

I suppose that does happen,   but often it is simply the perception of the child and not a reality.   Some children need more encouragement and praise than do others.   You, for example, may be self sufficient and a self-starter and your sibling may need to have someone push him along in order to succeed.   He may need constant praise in order to continue to do well.   You, on the other hand may be the child your parents can depend on to do well and they do not realize that you need more from them in praise department than they are giving.   Or...you may be the child that is lackadaisical in your studies or in your family responsibilities and they do praise your sibling more simply because he deserves it.   That may praise him more to make you see that you are lacking in some area (school work, home responsibility etc.) Because they "appear" to favor one child over another does not mean that they love one more than the other.   When more than one child is in a family it is not unreasonable for the parents to love them differently for different reason, it does not mean they love one less.   Each child has different personalities and need different motivations and less (or more) correction.   It is the parent's duty to find what works for each child.   As a general rule, parents may not always love what their child does nor does not do,   but they will always love their child.   What you see as favoritism, may be their way of coping with all their children.