Theory of Parent-Offspring Conflict

According to traditional evolutionary theory, parent-offspring relationships are seen from the parent's perspective. Parents are traditionally assumed to allocate investment in their young in such a way as to maximize the number of surviving, while offspring are implicitly assumed to be passive vessels into which parents pour the appropriate care.

If parental investment (PI) in an offspring is denned as anything done by the parent for the offspring that increases the offspring's chance of surviving while decreasing the parent's ability to invest in other offspring.


From the perspective of the parents, each person's total reproductive effort consists of both parental investment and mate-related work. The amount of parental resources allocated to each given child can vary depending on a variety of circumstances. The amount of parental involvement that each parent should make in their shared genetic offspring has the potential to cause conflict between parents.

Children vie with one another for access to parental resources. Conflict between parents and children can occur because some acts that improve an offspring's fitness could possibly diminish the parent's lifetime success, just as other behaviors that improve parental fitness could potentially reduce the lifetime fitness of a specific offspring.

The intimate genetic connection between parent and offspring is predicted to limit parent-offspring conflict. Any gene in an offspring that results in an additional investment decreases (to some extent) the number of surviving copies of itself found in siblings. For instance, if the offspring receives more investment than the parent has been selected to give, the offspring reduces the number of its surviving siblings.

Obviously, even if a gene confers some benefits to the offspring, it will be selected against if it imposes an excessive cost on the parent. One must explain how the offspring is expected to balance the survival of siblings against its own survival in order to determine precisely how much cost an offspring should be willing to impose on its parent in order to obtain a particular benefit.

What is the Theory of Parent-Offspring Conflict?

The theory of parent-offspring conflict is founded on the idea that parents have a certain quantity of resources to allocate to their children. This can include things like food, shelter, and even attention. On the other hand, Offspring desire to maximize their survival and reproductive success, which may or may not coincide with their nurtures' goals.

This conflict emerges due to hereditary inclinations that differ between parents and offspring. Parents want to maximize their reproductive success by having as many viable kids as possible. Offspring are concerned with maximizing their survival and reproductive success, including fighting with their siblings for limited resources.

In many bird species, for example, nurturers have a limited supply of food to feed their offspring. While it is in the guardians' best interests to distribute the food evenly among their children, each chick would benefit more if it received a larger share of the food, which causes competition for resources and survival. The hypothesis of parent-offspring conflict can present itself in various ways in humans.

Nurturers, for example, may wish their children to choose a career or life path that they believe would lead to success and pleasure. However, the children may have other interests and ambitions that do not correspond with those of the caregivers. This can lead to conflict between parents and children and possibly the dissolution of the parent-child relationship.

Researches Conducted on this Theory

The theory of parent-offspring conflict has been extensively researched in various animal species. The Nature study on burying beetles looked at the consequences of parent-offspring conflict on the evolution of body size and offspring behavior. Burying beetles exhibit complicated parental care behaviors, with guardians giving food and protection to their children. However, the guardians invested more resources in larger children, creating a conflict of interest between parents and offspring. The researchers changed the allocation of resources to the offspring to explore the implications of this conflict.

They discovered that the smaller offspring had a greater survival rate when the allocation was equal. The researchers also looked into how offspring behavior affected the dispute. They discovered that when their young were given less food, they became more aggressive and competed for resources. The researchers concluded that this conflict could significantly affect the evolution of body size and offspring behavior. They suggested that the conflict can drive the evolution of offspring behavior towards increased competitiveness and aggression.

Another study examined the consequences of parent-offspring conflict in mice, specifically the influence of stress during pregnancy on offspring behavior and survival. The researchers discovered that when moms were stressed during pregnancy, their children were more violent and less socially adept. This conflict emerges because the mother wishes to maximize her offspring's survival, while the offspring wishes to maximize their survival and reproductive success. In this scenario, stress exposure caused behavioral changes in the offspring, increasing their odds of surviving in a demanding and competitive environment.

The researchers observed the offspring's behavior in various social and competitive circumstances. They discovered that children born to stressed moms were more likely to engage in aggressive behavior and were less socially proficient than children born to non-stressed mothers. These characteristics aided offspring survival and reproductive success because they were better equipped to compete for resources.

Implications of the Theory

The theory of parent-offspring conflict has several important implications for our understanding of animal behavior, evolution, and human relationships.

  • Evolutionary Trade-offs − The parent-offspring conflict theory emphasizes the evolutionary trade-offs when guardians and offspring have competing goals. For example, nurturers may devote more resources to larger offspring, who have a better chance of survival and reproduction, but at the price of smaller offspring. Depending on the relative costs and rewards of various methods, this might result in the evolution of diverse features and behaviors in parents and children. Caregivers, for example, may develop to modify their investment based on environmental conditions or their kid's behavior. In contrast, offspring may evolve to compete more efficiently for resources or cooperate with siblings.

  • Parental Investment − The concept of parent-offspring conflict underscores the significance of guardian involvement in children. Parents may provide resources differently to each of their children based on their perceived odds of survival and reproductive success, which can lead to sibling conflict.Understanding how guardians allocate resources can help us better understand how their children develop and behave. For example, studies have shown that parents may spend more resources on offspring in poorer health or are more likely to survive, which can have long-term consequences for offspring fitness. The parent-offspring conflict theory has ramifications for our knowledge of animal social behavior. Offspring may compete for resources, leading to the emergence of cooperative or competitive behaviors. Similarly, parents may use various techniques to maximize their reproductive success, which can result in the evolution of various parenting styles. Some bird species, for example, practice cooperative breeding, in which non-breeding individuals help raise the offspring of others. This can help to lessen sibling conflict and boost the group's overall reproductive success.

  • Human Relationships − Parent-offspring conflict theory impacts our understanding of human interactions. Conflicts can emerge between nurturers and children, for example, when their aims and interests disagree. Understanding these conflicts can help us better understand the dynamics of family relationships and provide insight into conflict resolution. Parents, for example, may have different expectations for their children's academic or professional achievement, which can lead to conflict if the children have different objectives or priorities. Similarly, children may have different expectations of their parents' engagement or support, which can lead to conflict if these expectations are not satisfied.


Subsequently, the theory of parent-children conflict is an essential concept in evolutionary biology because it emphasizes the complex dynamics between guardians and offspring. It has far-reaching implications for how we think about evolutionary trade-offs, parental investment, social behavior, and human relationships. Understanding these conflicts allows us to acquire insights into organism growth and behavior and how to handle conflict in family relationships.

Updated on: 05-May-2023


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