JUN 22, 2019 3:20 PM PDT

Do We Inherit Our Instincts?

WRITTEN BY: Annie Lennon

Some things are just instinct. For example, a mother’s urge to look after her young is generally considered an instinct, as is a spider’s ability to construct a web. But where does this behavior come from?

There are several different theories that try to explain this. One explanation is that instincts are the result of a combination of epigenetic changes and environmental stimuli experienced in one’s lifetime. For example, researchers have found that mice exposed to Vinclozolin, a substance used to manage diseases such as blights and molds in vineyards, experienced changes in their DNA packaging, which was then passed on for three generations (Yirka: 2017).

Researchers have also found that mice taught to react calmly to stress influence their offspring’s response to stress too, which leads them to have a calmer response to stress as well. This behavior may also be carried on to a third generation. Although there is still no evidence supporting the notion that epigenetic changes necessarily convert into DNA changes, given that instinctive and learned behaviors likely run on the same neural circuitry, some suspect that our instincts must be derived from learned behaviors in the past (ibid.).

To understand how this process may happen in more detail, it is interesting to delve into how we learn in the first place. Synapses, structures that permit neurons to pass on electric and chemical signals to other neurons, are regarded as being key to learning and memory (Kennedy: 2016). The communication that they enable between neurons has been connected to our ability to perform certain tasks. This is why, when confronted with a new task, unless we have done something similar to it before that activates similar neural pathways, we may initially struggle. Practice of this task however should, in theory, optimise the way our synapses function as they improve the connectivity between neurons based on feedback loops (Picard: 2013).

For instincts to happen, it appears that the genes responsible for constructing synapses set their functions to ‘adult’ values during embryonic development. This means that, unlike when we learn something for the first time, our synapses are fully reactional to a given environment as if they have already gone through a rigorous learning phase (Tryon: 2018). Such inheritance of instincts seems to have a particular effect on spiders, in how they manage to spin their webs soon after hatching, as well as on cats and dogs- why they behave differently. Yet, despite our understanding of how instincts are likely passed on through generations, the process behind how our genes construct synapses at adult values during embryology is still unknown.

To conclude, although there appears to be something of a biological basis as to how we inherit certain behaviors, how exactly they become encoded into our genetics is uncertain. Although epigenetics goes some of the way in demonstrating how certain behaviors may linger between generations, the process behind the creation of fully functional adult synapses that are passed on continuously is yet to be discovered.

 

Sources

 

Yirka, Bob: Phys.org 

Kennedy, Mary B.: PMC

Picard, Nathalie et al: Nature

Tryon, Warren W.: Psychology Today 

About the Author
  • Science writer with a keen interest in behavioral biology, consciousness medicine and technology. Her current focus is how the interplay of these fields can create meaningful interactions, products and environments.
You May Also Like
MAY 11, 2021
Cell & Molecular Biology
Problems in Human Egg Fertilization Are Common
MAY 11, 2021
Problems in Human Egg Fertilization Are Common
This ©MPI for Biophysical Chemistry microscopy image shows a bovine egg after fertilization.
MAY 17, 2021
Genetics & Genomics
Diagramming Connections in the Brain with Barcodes
MAY 17, 2021
Diagramming Connections in the Brain with Barcodes
The billions of neurons in the brain form a complex network, as shown in this image from CSHL scientists Xiaoyin Chen an ...
MAY 26, 2021
Genetics & Genomics
Connecting Bacterial Genes to Human Disease
MAY 26, 2021
Connecting Bacterial Genes to Human Disease
This kind of research gets us closer to using fecal samples to get a snapshot of the microbiome, and make disease risk p ...
MAY 28, 2021
Genetics & Genomics
Some Biofilms Seem to Activate Cancer Genes
MAY 28, 2021
Some Biofilms Seem to Activate Cancer Genes
New research assessed bacterial and fungal biofilms, tenacious microbial communities that are tougher than small groups ...
JUN 25, 2021
Genetics & Genomics
Towards More Efficient Plant Engineering with CRISPR-Cas9 Gene Drive
JUN 25, 2021
Towards More Efficient Plant Engineering with CRISPR-Cas9 Gene Drive
Many people in the world don't have access to enough food. And while humans might find ways to adapt to a changing world ...
JUL 18, 2021
Genetics & Genomics
Researchers Find Strange 'Borg' DNA - It's Assimilating
JUL 18, 2021
Researchers Find Strange 'Borg' DNA - It's Assimilating
Our environment is full of DNA molecules. While researchers have become concerned about DNA waste material that's ac ...
Loading Comments...