Socialization of animals
Socialization of animals is the process of training animals so that they can be kept in close relationship to humans. Dogs. The critical period of socialization commences when they are approximately three weeks old and will continue until they are twelve to fourteen weeks old, during which they move to the next stage of development, the juvenile period. This period of socialization is the time when puppies form social bonds, learn to explore and learn when/how to base fear. Additionally, this stage consists of teaching them how to appropriately react and habituate to environmental changes in  preparation for adulthood. Habituation is the process when a puppy has gotten used to stimuli in their environment and therefore ignores it, deeming it non-threatening. The puppy's future personality will be greatly influenced during the socialization period. Their temperament and character is developed throughout this period as well, which will last for the duration of their life. During the socialization stage, all five senses are being stimulated by exposure and desensitization of sights, sounds, tastes, smells and touch of things around them. It is critical that human interaction takes place frequently and calmly from the time the puppies  are born, from simple, gentle handling to the mere presence of humans in the vicinity of the puppies, performing everyday tasks and activities. As the puppies grow older, socialization occurs more readily the more frequently they are exposed to other dogs, other people, and other situations. Dogs who are well socialized from birth, with both dogs and other species (especially people), are much less likely to be aggressive or to suffer from fear-biting. The cognitional development of puppies can be affected when the critical period of socialization is disrupted. Physiological consequences of this period not occurring can lead to  puppies maturing to adults who are not able to react appropriately to new environments, situations or people. Additionally, behavioural issues can arise. Aggression, avoidance and fear are just some of the implications that can arise from a puppy not achieving the critical period of socialization. It is estimated that one in four adult dogs have at least one behavioural problem. Dogs are the animal which is typically the most closely attached to humans, developing tightly wound relationships with people. Therefore, it is crucial for the safety of both parties that there is adequate training in place. Dogs experience socialization through  the critical period of socialization in two main types: active and passive. Active implies the intended socialization of humans introducing their puppy to something/someone new (i.e. at obedience class or a ride in the car). However, passive involves socialization of the puppy to something/someone new in which they have done so unintentionally themselves (i.e. insects found in the backyard while exploring or items found while running around the house). Dogs will often learn two ways; by association and consequence. Learning by association is classified as classical conditioning, while learning by consequence is called operant conditioning. With puppy socialization , classical conditioning involves pairing something they love with something within the environment. Additionally, operant conditioning involves the puppy learning to do something to achieve getting what they want. These two learning types can occur simultaneously with a puppy having the ability to learn both an internal and external response to a stimulus. In contrast, a puppy can also demonstrate methods of actively avoiding a situation they do not enjoy. Socialization experiments. Using puppies. The researchers, Fox and Stelzner did a socialization experiment on puppies of the same species. The major finding of this experiment is the fact that the puppies  weaned from the mother at a later age (12 weeks) have better socialization skills. This proves that the beginning of a puppy's life is a very important time for socialization and will affect their social tendencies for the rest of their lives. Hennessey, Morris, and Linden conducted a socialization experiment using inmates as handlers of the shelter dogs being studied. These researchers found that the dogs in the experimental group did not jump on and bark at unfamiliar humans as much as the dogs in the control group did. The socialized dogs also showed to be more responsive to  commands than did the dogs in the control group. The researchers believe that through more effective socialization, more dogs can be adopted from shelters. Battagalia claims that there are 3 important periods during the first year of life for a puppy. Her research shows that if puppies experience stimulation from humans during the first few months of their lives, they will be less likely to feel stress in their adult lives and they will be better socialized. She claims this is a very important thing for dog breeders to know to improve the success of their puppy's future lives . Using dog and wolf puppies. A study done by the six researchers, Topál, Gácsi, Miklósi, Zirányi, Kubinyi, and Csányi compares the inherent social tendencies between dog puppies and wolf puppies. What these researchers found was that dog puppies showed attachment to their owners and showed to be more responsive to their owner than an unfamiliar person. The wolf puppies did not show to be more responsive to their owners than to an unfamiliar human. Researchers concluded that this is a genetic difference between species. These six researchers attempted to answer the question, "Why?" in their next experiment. They found that  dogs were more successful in finding hidden food and in completing a learned task than wolves were. The most prominent observation these researchers made was that the dogs would look into the eyes of the human as if looking for a clue and the wolves would not look at the faces of the humans. They concluded that this is a genetic difference between the two species as a result of evolution. Monkeys. Monkeys are often studied because of the close evolutionary relationship between monkeys and humans. Like humans, some monkeys tend to show declining social activity with age. Research has  shown that older females spent less time grooming other and interacted with fewer animals than younger individuals did. Socialization experiments. Bernstein and Ehardt conducted an experiment on aggressive behavior of rhesus monkeys. They found that the monkeys showed more aggression towards kin than non-kin, mostly from older kin to younger kin. This supports the hypothesis that aggression is used in socialization and correction of inappropriate behaviors in the immature monkeys. If the aggression is no more severe than is needed to correct the behavior, it can improve the survival rate of all the relatives. In 1980, Berman researched the  mother-infant relationship of rhesus monkeys both in the wild and in captivity. She found many similarities between the two parenting styles but some minor differences. The captive mother has been described as more protective and less willing to let their infant out of their control. The difference that likely has to most effect on this relationship is, the wild monkey has kin around which helps with the socialization of the infant, and the mother in captivity does not. This shows how environmental factors can affect the early socialization of infant rhesus monkeys. Socialization at a young age has been  seen to affect sexual behavior in the adult rhesus monkey, in a study done by, Gold, Wallen, and Goldfoot. This is not seen as prominently in rats, and other small animals as it is in primates. The monkeys have difficulty acting normally even when a sexual opportunity presents itself, this is due to the fact that they have affectional disorders that they do not often overcome. It is very difficult to study the lives of isolated children so researchers have turned to studying the effect of total isolation on rhesus monkeys. Completely isolated monkey's first response to stimulus is  fear or aggression. They do not learn any normal socio-emotional skills. When these monkeys are able to come in contact with a group, they do not know how to interact and would not be able to survive in a group.