Myth 2 Myth 2: Good causal explanations of the development of behavior must proceed up from the genes, nervous system, or hormones. Causation is never from the top down. – This comes from the view that the best scientific explanations ultimately come from the more basic sciences because organisms are composed of the things physicists, chemists, and molecular biologists study – Therefore, causal explanations must go from the bottom up and developmental processes are ultimately explained by the basic sciences on the upward causation only view. – As we will see, however, this ignores organismal composition and how components at different levels of organization interact – When the components of a biological system interact, we have networks of causal interactions – With networks, there can be causal loops that connect different levels of organization (e.g., gene expression to behavior and behavior to gene expression)
Five Myths of Developmental Psychobiology PSC 113 Jeff Schank
Myth 1 Myth 1: Development, including behavioral development,
proceeds according to a program or blueprint represented in the
genes. As we will see, the development of organisms is not
regulated by a program encoded in an organism's genes, nor is
development represented as a blueprint in the genes. Instead,
development is an epigeneic process (i.e. a process of emergent
development in which stages emerge from the conditions present at
previous stages such as environmental factors, gene regulation, and
expression; not to be confused with epigenetics). Genes do not
function as programs or blueprints but rather they function in
networks (much like neural networks), which interconnect to other
networks at different levels of organization. Myth 2 Myth 2: Good
causal explanations of the development of behavior must proceed up
from the genes, nervous system, or hormones. Causation is never
from the top down. This comes from the view that the best
scientific explanations ultimately come from the more basic
sciences because organisms are composed of the things physicists,
chemists, and molecular biologists study Therefore, causal
explanations must go from the bottom up and developmental processes
are ultimately explained by the basic sciences on the upward
causation only view. As we will see, however, this ignores
organismal composition and how components at different levels of
organization interact When the components of a biological system
interact, we have networks of causal interactions With networks,
there can be causal loops that connect different levels of
organization (e.g., gene expression to behavior and behavior to
gene expression) Myth 3 Myth 3: Since ontogeny does not
recapitulate phylogeny, and evolution and development occur on
different time scales, the sciences of evolution and development
can proceed relatively independently of each other In this view,
the study of psychological and behavioral development in organisms
can proceed independently of the study evolution But, to survive
and reproduce, organisms must not merely be adapted as adults, they
must have adaptations specific to the ontogenetic niches they
inhabit during development Likewise, the study of evolution cannot
ignore the constraints imposed by development on the evolution of
organisms. Myth 4 Myth 4: The only mechanism for transmitting
information developmentally from one generation to the next is gene
transmission This is the view that the trans-generational
information necessary for the development of offspring is not
solely transmitted from parents via the genes There are other modes
on informational transfer from generation to generation (e.g.,
epigenetic and cultural transmission) Myth 5 Myth 5: The causes of
behavior can always be partitioned into that component due to
nature or nurture (i.e., nature + nurture = behavior) Nature vs.
nurture is a misleading distinction Nature is typically taken to
mean genes and nurture to mean experience Understood this way, the
distinction fails to recognize that genetic and experiential
components are parts of interacting networks that span multiple
levels of organization Because of these interactions, we cannot
completely partition causes into proportions caused by nature and
by nurture Can we learn anything from ants? Is complexity simple?
Ants
