Considering the innumerable studies that have been made in relation to the family and from different perspectives, without a doubt, the family continues being quite a complex group to approach for every kind of professionals: social anthropologists, psychologists, social workers, etc. Due to their enormous quality of change, always in constant flux, and its adaptation to the needs and contexts, according to time, space and situations that are being lived at the moment, we must not ignore that it is the very foundations of society, that is to say, that what happens to it is reflected in the streets, schools and neighborhoods.
The family is the social group, which in a natural way, independently of the laws that rule our society, - maybe as a survival instinct - is unconsciously in charge to transmit, conscientious or unconscientiously, religious, cultural, moral, among other type of values. It plays the role of training for individuals and, by means of it, a town can be developed in a sum of aspects as economical, technological, political, etc. but, on the other hand, it can degenerate and also sink.
Even though, the word family is well known by everyone and it is included in our common language, it is possible to make certain explanations on this matter, especially in its definition:
- “The family has, in almost all societies, the reputation of an institution and generally represents the nucleus of a greater condensation of the kinship systems”. 
- It is truth that the family exists in all societies of the world; nevertheless its structure, size, composition and functions vary according to the culture it belongs, historical moment, even to the needs and decisions within it. For example: in a society, as the Mexican, exists different types of families, from the traditionally composed by the parents and children (nuclear), the one formed by parents, children and other members with which it shares a blood line (extensive), the single parent families (uniparental), and the families with the presence of step parents and step sons (assembled), to the those composed only by the pair (conjugal).
By such reason, it is advisable to consider that exist a range of
definitions from which must be chosen the following:
Murdock (1949) indicates that the family "is a social group characterized by a common residence, the economical cooperation and reproduction. It includes adults of both sexes, from which at least two of them maintain a socially approved sexual relationship and have one or more children, being biological or adoptive, under the custody of the adults who sexually cohabits”.
"It designates a social group formed by people bonded by blood, marriage or adoption, characterized by a common residence, economic cooperation, reproduction and raising of the descendants". 
"Group of individuals typically represented by a father, mother and children, but which also include groups where lacks one of the parents, or groups that include other adoptive relatives, children, and, in some cultures, slaves and crew members". 
The FAMILY is a fundamental unit of the SOCIAL ORGANIZATION, composed as
a) Two individuals of opposite sex that coexist in a stable way, in the same house as the result of some type of marriage; maintain a sexual and affective relationship, regularly cooperate in the material reproduction of their existence by distributing their tasks inside and outside the unit and whose coexistence, concerning sexual and affective treatment, economical cooperation, is approved and recognized as legitimate - in exchange for the conformity of certain SOCIAL NORMS, in the first place those that regulate marriage - by the society which they are part of.
b) Two individuals of indifferent, equal or different sex, united by relation of direct biological ancestry/descendants (replaced sometimes by relations of adoption), which coexists in a stable way and cooperates at least in the economical plane - although in some cases that cooperation can be limited to the maintenance of the descendants by the parent -, whose biological ancestry/descendants relations of coexistence and economical cooperation are also approved and recognized as legitimates by society. Always in exchange for the conformity towards certain norms. 
"A group of which foundations are related to consanguineous bounds". The family is the result of a long historical process, whose present form of monogamist character is the conjugal pair.
In its ample meaning, the word family makes compatible reference to the set of ascendants, descendents, and collaterals sharing a common genetic trunk. Analogically it is said that what constitutes a family is a group of individuals who share relations of origin or similarity. 
Independently of the numerous efforts, agreements and differences that define the concept of FAMILY, it corresponds to mention that this occurs in two levels, one that depends on the acceptance and social recognition which is followed by a series of legal rights and obligations according to its context, and by the identification and recognition of the own family on its inner perspective, which not necessarily has a social and legal recognition. In such way, those who integrate it try to fulfill with what they consider their obligations, being implicit and/or explicit.
Therefore, the FAMILY is the social group of greater importance and
indispensable for the existence, survival and development of the human being.
It is, undoubtedly, the fundamental and determining part for the development, stagnation or decay of a society. Inside of it values are developed to fortify respect, solidarity and identity, self-esteem of their members, but also hatred and resentment. Egoism is generated, scorn towards oneself and the family, which is reflected in society and are also fed back as well, according to the predominant moral values.
At the present time, the existential crisis of the Mexican families is well-known. The progressive increase of homes with poor maternal and/or paternal presence generates a premature independence of the children and, in addition, weak affective bounds between parents and children, the education and formation of these, that in combined stages, are delegated to institutions or people outside the family, which this is not emotionally satisfactory to the children. Consequently the values are not empirically acquired alongside their parents. It is then when besides the institutions and babysitters, that television, videogames and the internet become part of their moral formation.
In a marriage each side fights for its independence and has its own interests. They are not agreeing all the time or they try to have common interests of pair or family. At the same time, each one individually procures to cover what they need and want; indifference and discussions are two frequent elements in the life of any couple. The possibility of a separation or divorce is present in their lives, decision that is not easy for them, but it does not take them a lot of effort either. They only have to make an arrangement for the goods and custody of the children, commonly in that order.
As a result of those family dynamics, children suffer of a severe affective deficiency, a disorder in relation to the moral values derived from the incongruent speech and acts of their parents. This converts the children into excessively vulnerable beings; they do not count with sufficient elements which allow them to identify and protect themselves from problems such as: addictions, gangsterism, sexual promiscuity, pregnancy in adolescents, management of suicidal ideas, attempts of suicide and suicide itself, among others. This it is the present panorama of the Mexican families.
1. GALLINO Luciano, Diccionario de Sociología, Ed. Siglo XXI
2. GINER, LAMO DE ESPINOSA Y TORRES. Diccionario de
Alianza Editorial, Madrid, 1998.
3. C. WARRE Howard (compilador), Diccionario de Psicología,
Ed. Fondo de Cultura económica.
4. GALLINO Luciano, Diccionario de
Ed. Siglo XXI
5. ADDER-EGG Ezequiel. Diccionario de Trabajo Social.