Polar bears are essentially solitary as it pertains to their social skillset. There are two social forms relative to the mammal’s inherent nature.
Social unit number one:
The first social unit is comprised of a) natural attraction between the male and female polar bear. Second is the social interaction that the mother polar bear possesses and displays toward her young. Therefore, the composition of Unit One respective of social behaviors amongst polar bears is as follows:
The adult female presents motherly instincts toward her bear cubs; and,
Two polar bears, male and female, make a connection; resulting in eventual parenthood. (However, it is the mother who cares for the cubs. The father does not participate in the parental role as nurturer.)
Social unit number two:
The second social unit, relative to polar bears consists of the following three activities:
1. Smorgasboard – polar bear style:
The cold weather creatures will get together to enjoy feasting on the carcass of a whale.
2. The vacationing polar bear:
Polar bears may get together as an aggregation or group, during the ice-free summer and fall months within regions where icy cold weather is not consistent. The bears will lounge about within these locations—essentially biding their time (so to speak) until winter’s chilly winds finally return. Polar bears which take up coastal land space during the warmer months awaiting for colder conditions are found in the Hudson Bay region: or, more precisely, James Bay which is situated at the southern leg of the Hudson Bay. The Hudson Bay extends from the Arctic Sea to the Atlantic Ocean. The world’s second largest bay is located in portions of Canada and parts of the northern United States. 
3. The old boy’s club – no female polar bears allowed!:
There are occasions, the male polar bears will form groups: traveling, hunting and subsequently feeding on prey, together. However, slightly contrary to the sub-title, the polar bear male groups may consist of adult males; and sub-adult males, alike. (The age range of the preceding traveling male mammals is anywhere between two and one-half years old and six years old.)
Following is a compilation of the general social interactions associated with polar bears. Some of the social interactions presented below may somewhat overlap the preceding information.
1. Mama and her bear cubs present the most common polar bear type of social interaction:
The polar bear mother demonstrates a great deal of attentiveness to her cubs: making certain they stay well-groomed. She attends to them with the utmost of motherly care. The latter statement implies Mama polar bear constantly nurtures and cuddles her bear cubs; and is very responsive in assuring they have plenty to eat.
2. It takes two:
The breeding pair of polar bears will remain together for a minimum of seven days or possibly longer: however, not by much.
3. Male aggression relative to one polar bear’s interaction with that of another occurs frequently during the season of breeding:
A male bear may try to steal food from another male bear wherein the latter bear was the official hunter; and the rightful owner of the “catch.”
4. Male polar bears while young will playfully fight with each other:
The male bear playfully fights with other male bears while he is young. The social activity is useful to him later when it becomes necessary he fend off the advances of other male bears. Generally, as already mentioned, the male bear is required to address the aggressive attempts of food-stealing by other male polar bears after he has hunted and subsequently captured a food source.
5. The young polar bear’s social interaction with his or her siblings:
The young polar bear will playfully chase after; and then tackle his or her brothers and sisters.
2. http://www.seaworld.org/animal-info/info-books/polar-bear/behavior.htm (article information)