The PRice “equation” for individually evolving: Which equation describes your life?

I’ve lightheartedly abstracted the Price equation for evolving populations to develop the eponymous PRice “equation” for individually evolving.

The details of the Price equation for evolving populations are presented in this (pdf) 2012 paper. [1] From the Introduction:

“Evolutionary theory analyzes the change in phenotype [the composite of an organism’s characteristics, including its developmental, biophysical, and behavioral traits] over time.

How does a phenotype influence its own change? Can we separate that phenotypic influence from other evolutionary forces that also cause change?”

The Price equation for evolving populations describes how:

  1. An ancestral phenotype exists with certain characteristics;
  2. It evolves and changes, resulting in
  3. A descendant phenotype that has different characteristics.

Greatly simplified:

  • Total change equals
  • Evolutionary changes caused by selection, plus
  • Changes caused by non-selection factors.

Other items:

“The Price equation can be expanded recursively to represent nested levels of analysis, for example, individuals living in groups.

Much of creativity and understanding comes from seeing previously hidden associations. The tools and forms of expression that we use play a strong role in suggesting connections and are inseparable from cognition.”


Applying the “How does a phenotype influence its own change?” question to a person:

How can a person remedy their undesirable traits – many of which are from their ancestral phenotype – and acquire desirable traits?

The PRice “equation” for individually evolving to change one’s own phenotype postulates:

  1. A person’s life was patterned by acquired characteristics that influenced their ideas, biology, and behavior;
  2. With the timing, duration, and intensity of a person’s efforts to effect changes in their life self-determined, they access impaired areas and therapeutically resolve the sources of the damage; resulting in
  3. A life that’s better fitted to “influence its own change” as their ideas, biology, and behavior become less driven by accumulated conditions.

Hypotheses of the PRice “equation” for individually evolving, with evidence for these hypotheses linked from studies I’ve curated and their references:

  1. The periods of our most profound changes – in utero, infancy, and early childhood – were also when many of our undesirable changes occurred.
  2. The root causes for many of our undesirable changes were that our basic needs weren’t met during these periods.
  3. The largest impacts of early unmet needs were epigenetic changes.
  4. Such adaptations didn’t unassistedly disappear over time, and they’ve continued to influence our ideas, biology, and behavior.
  5. We can ameliorate undesirable acquired characteristics without outside actions being done to us.

Both the problems and the “cures” are usually externally applied in animal studies. Can early-life causes for later-life problems be approached in other ways with humans?

Animal studies show what approaches don’t work. For example, the effects of stress induced by maternal separation during a rat pup’s infancy and early childhood aren’t reversed by returning it to its mother later in life. The separation encompassed critical periods only during which the mother could satisfy the pup’s needs. After critical periods, the mother’s actions would be too late. The pup’s development deviated from the norm with biological adaptations.

There are many ways to suppress undesirable effects and symptoms later in life. These can’t be recommended as primary methods for changing one’s own phenotype, though, because efforts to alleviate symptoms seldom remedy the underlying causes of the symptoms.

Studies that found some acquired characteristics to be state-dependent include:

These animal studies used drugs to initiate and recreate the states. If the findings of studies such as Are 50 Shades of Grey behaviors learned in infancy? are extendable to humans, it’s likely that human emotions and physical reactions can also initiate and recreate such state-dependent memories.

When undesirable acquired characteristics are state-dependent, an approach to ameliorating them may involve:

  1. Returning to the initial environment;
  2. Reentering the state where the undesirable characteristics were acquired; and
  3. Addressing the underlying causes of these symptoms while in that state.

It’s unlikely that people can therapeutically resolve underlying causes if the timing, duration, and intensity of efforts are externally determined. An individual’s efforts should neither use forcible approaches with drugs, etc., nor be primarily directed on someone else’s schedule.


This 2015 study and its commentary Evolutionary paths of least resistance show how “other evolutionary forces that also cause change” components of the Price equation may operate:

“Evolution may preferentially mitigate damage to a biological system than reduce the source of this damage.”

Even “evolutionary paths of least resistance” alleviate symptoms rather than:

  • “Reduce the source of this damage” and
  • Enable a life that’s better fitted to “influence its own change.”

There are also non-evolutionary obstacles to applying the “How does a phenotype influence its own change?” question to a person:

  1. Research usually isn’t primarily directed toward producing causal evidence for the above five PRice “equation” hypotheses. Studies performed in relevant areas are typically designed to produce symptomatic evidence.
  2. The process of a person remedying their undesirable traits and acquiring desirable traits isn’t pain-free. A choice that involves pain is understandably a decision that few of us would make, even when it’s part of an optimal solution.
  3. A person’s time and other resources.

Pain avoidance, and the lack of relevant information and resources combine to become a high hurdle. Most people’s lives aren’t suited to “influence its own change” as a result.

Which equation describes your life? What are you doing to change your phenotype?


[1] See http://stevefrank.org/pub-date.html for more. I recommend this (pdf) commentary on cancer research and how its progress may be affected by researchers’ typical disinterest in historical frameworks.

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