Editing Vervet monkey (section)

=== Kin relationships ===
Siblings likely provide the prevailing social relationships during development. Within social groups, mother-offspring and sibling interactive units are distinct groups. The sibling interactions are heavily supportive and friendly, but do have some competition. Contests primarily involve postweaning resource allocation by the common mother. For example, siblings have conflict over grooming time allocated by their mother. Offspring are usually not born in extremely close time proximity due to the interbirth period of the mother. This time can be reduced by use of an [[Alloparenting|allomother]]. The clarity of the familial and sibships within a group may act as a form of alliance, which would come at relatively low cost in regards to grooming. Other alliances are shown through conflict with aggressive individuals that have acted against a closely related sibling.<ref name="sibships">{{cite journal| last = Lee| first = P.C.| title =Sibships: cooperation and competition among immature vervet monkeys|journal =[[Primates (journal)|Primates]]| volume =28| issue =1| pages =47–59| date =1987| doi = 10.1007/BF02382182| s2cid = 21449948}}</ref>
[[Image:Vervet monkey and baby.jpg|thumb|left|Vervet monkey female with a baby]]

Allomothering is the process when another individual besides the mother cares for an infant. In groups of vervet monkeys, infants are the target of a tremendous amount of attention. Days after an infant is born, every member of the group inspects the infant at least once by touching or sniffing. While all group members participate in infant caretaking, [[juvenile (organism)|juvenile]] females that cannot yet [[menstruate]] are responsible for the majority of allomothering. The benefit is mutual for the mother and allomother. Mothers that use allomothers are able to shorten their interbirth periods, the time between successive births. At the same time, allomothers gain experience in rearing infants, and had more success in raising their own offspring. Juvenile females discriminate in preference for the infant they choose to allomother, and usually choose siblings or infants of high-ranking individuals. When a mother allows her juvenile daughter to become an allomother for a newborn sibling, the mother decreases her own investment in the infant, while increasing the chances of successful rearing of her immature daughter.<ref name="allomother">{{cite journal| last = Fairbanks| first = L. A.| title =Reciprocal benefits of allomothering for female vervet monkeys|journal = [[Animal Behaviour (journal)|Animal Behaviour]]| volume =40| pages =553–562| date =1990| doi = 10.1016/S0003-3472(05)80536-6| issue = 3| s2cid = 53193890}}</ref>

Grandmothers and grandchildren share one-quarter of their genes, so they should be more likely to form affiliative relationships than unrelated members in a group. Not only do infants approach their grandmothers more often than unrelated members, but they also prefer their grandmothers compared to other adult female kin, not including their own mothers. Additional research has shown grandmothers show no preference over the sex of their grandchild. Interest in the grandchild spurred from the rank of the grandmother within a group. Higher-ranking grandmothers showed more interest in caring for their grandchildren when compared to low-ranking grandmothers. The presence of grandmothers has been associated with a decrease in mortality of infants.<ref name="grandmothers">{{cite journal| last = Fairbanks| first = L. A.| title =Vervet monkey grandmothers: interactions with infant grandoffspring| journal = [[International Journal of Primatology]]| volume =9| issue =5|pages =426–441| date =1988| doi=10.1007/bf02736218| s2cid = 6784648}}</ref>