Legal Question in Family Law in Massachusetts

Re: MA law

Massachusetts specifically defines those types of kinship which prohibit marriage. A brother may not marry his mother, sister, etc. First cousins, however, are allowed to marry.

The legal aspect of marriage to blood relatives reflects the fact that the genetics of intermarriage are difficult, and that there are psychosocial problems as well. You should not marry anyone of close kinship unless you are prepared to work through possible genetic issues, your own issues, and the family dynamics that will be disrupted.