宗系遗传(descent)
公认的社会家系体制，各个社会都不相同，一个人可以据此宣称和另一个人有亲属关系（kinship）。宗系遗传制度的实践意义在於，一个人可以据此申明自己的权利、义务、特权或地位。当以亲属关系决定继位、遗产继承（inheritance）或住宅继承时，宗系遗传制度具有特殊影响。限制亲属关系之认同的方法之一是仅强调双亲中一方的种种关系。这种所谓「单系」亲属制度有两种主要类型︰父系（或男系）制度强调父亲方面的种种关系；母系（或女系）制度强调母亲方面的种种关系。单系制度与所谓同族制度大不相同，根据同族制度，每一个人对父系及母系亲属负有同样的义务及责任，反过来也可以从父系及母系亲属指望获得同样权利和特权。在结构上，并从权利及义务上讲，同族制度是模糊的，趋向於成为工业化程度较高的国家的特性，在这些国家，个人的权利及义务日益为制度及法律所规定。
English version：
descent
System of acknowledged social parentage whereby a person may claim kinship ties with another. Descent systems vary widely. The practical importance of descent comes from its use as a means for individuals to assert rights, duties, privileges, or status. Descent has special influence when rights to succession, inheritance, or residence follow kinship lines. One method of limiting the recognition of kinship is to emphasize the relationship through one parent only. Such unilineal kinship systems are of two main types—patrilineal systems, in which the relationships through the father are emphasized; and matrilineal systems, in which maternal relationships are stressed. These systems differ radically from cognatic systems, in which everyone has similar obligations to, and expectations from, both paternal and maternal kin. The cognatic system is somewhat vague and tends to characterize the more industrialized countries, in which individual rights and duties are increasingly defined institutionally or legally.