Week 7 Readings Flashcards
Individual differences in cognitive performance: impact on fitness
Studying evolutionary changes in physical and reproductive traits can be studied in natural populations over short time scales.
Changes over a short time scale occur if they’re heritable and influenced by Darwinian fitness (e.g., human intelligence, g, is linked to fitness traits such as increased health and lower mortality rates).
How do we study this in non-human animals? With an evolutionary ecology approach.
> on captive animals (i.e., learning improves
the reproductive fitness of male fruit flies
by reducing time wasted on courting non-
reproductive females and is heritable)
in laboratory studies (i.e., under certain
environmental conditions intelligent/smart
reproduce more and produce evolutionary
changes in a short time scale within
artificial populations).
Can these links between cognition and evolutionary fitness exist in the wild?
> Male bowerbirds that can solve novel
technical problems faster than their peers
tended to have more coupluations (i.e.,
sex)
great tits (avian species) greater problem
solvers produced more offspring but their
offspring did not have a greater chance of
survival. This mismatch is not surprising
considering that 90% of avian offspring die
within the first few months of life.
*laboratory and field studies show the link
between cognition and selection but not in
the wild thus far.
experimental evolution laboratory studies indicate that there are fitness trade-offs (i.e., individuals with higher cognitive performance were less able to compete for food, more likely to desert their offspring before they left the nest; this is due to the added costs of remembering, collecting, and using the information in higher intelligent individuals).
The link between cognition and fitness could be masked by behavioral traits such as personality which impact both variables.
Benefits of an individual-based evolutionary ecology approach
experimental manipulations, comparisons between populations and species, and theoretical models all provide complementary approaches to the study of cognitive evolution in non-human animals and provide testable hypotheses.
Comparisons:
> individuals with better spatial memory are
better able to survive harsh winters (i.e.,
more hippocampal neurons, more accurate
spatial memory, faster habituation, and
more rapid innovative problem-solving
more prominent in Alaska black-capped
chickadees who survive harsh winters
rather than those found in Kansas) =
intensity of seasonal variation is a strong
influence on the evolution of cognition.
> social competition, food availability, and
environmental variations are known to
drive selection and evolution on cognition.
Evolutionary Models:
> predicts that living environments with
predictable events over an individual’s
lifetime should lead to selection for
increased reliance on learning, especially
when there is variability in the environment
between generations.
> Invasion by novel prey species or range
expansion into new habitats may produce
drastic changes in ecological conditions
and novel selection pressures for
behavioral and cognitive traits.
Functional links between cognition and fitness
problem-solving in great tits is associated with increased clutch size and number of fledglings, but not with offspring body conditions (both male and females). This indicates that innovative problem solving is important for determining foraging efficiency during egg-laying, when food is scarcer, and when males feed their mates.
this is further supported by evidence that the size of the area around the nest used to search for food (i.e., home range) was half as large for birds who were good problem solvers.
Summary points
individual-based approaches can reveal what role short-time evolutionary processes have in driving cognitive variation in extant populations.
the challenge is that cognitive traits have cognitive and non-cogntive components which make them hard to standardize across individuals. Therefore, it may be better to study them together.
the intersection between ecology, psychology, and neurosciences provides new avenues of research.
Great Apes Anticipate that Other Individuals Will Act According to False Beliefs
Summary & Conclusion
Theory of Mind: the ability to understand that others’ actions are driven not by reality but beliefs about reality, even if they’re false.
Although humans and apes share socio-cognitive skills they’re repeatedly filed traditional false-belief tasks.
The use of anticipatory looking tasks illustrates that apes loo in anticipation to where agents falsely believe the object to be rather than where they know it to be. This implies that apes have at least an implicit theory of mind.
Study
Introduction:
> culture, communication, cooperation, and
theory of mind make humans distinct from
non-human animals.
> non-verbal behavioral experiments have
provided converging evidence that apes
can predict others’ behavior based on
unobservable internal states rather than
external observable behaviors.
> however, until now it remained unclear
whether they could comprehend false
beliefs where reality and belief are not
matched.
> the use of anticipatory looking tasks in
human infants reduces executive function
demands and means infants below the age
of 4 can pass modified false belief tasks
(VOE and anticipatory looking are used to
see if participants can predict an agents
behavior before they do it).
> two studies that used these methods with
monkeys showed they failed false belief
tasks.
> The current study uses these methods to
assess tom in apes (chimpanzees, pan
troglodytes, bonobos, pan paniscus,
orangutans, pongo abelii). Apes have been
shown previously to anticipate agents’ goal-
directed behavior based on event
memories (true beliefs).
Methods:
> ape’s eye gaze towards a video scene was
non-invasively measured using an infrared
eye-tracker.
> They watched two familiarization videos,
followed by a single test trial (either FB1 or
FB2). Where the location of the object was
changed when the actor was absent and
now holds a false belief. Do they act on the
agents false belief or where we know the
object to be?
> anticapatory look either to the target (FB
location) or the distractor (actual location)
Results:
> Apes made significantly more first looks at
the target than to the distractor, overall and
in each condition.
> No significant difference was found across
species.
> They concluded that apes successfully
anticipated where an agent would look for
an object when they held a false belief
about its location.
Confounds it Controls for:
> that infants are looking for the object in the
first or last location it was hidden.
> they could respond to violations of three-
way associations (the actor, the target
object, the object’s location) formed in the
belief induction or familiarization phase.
> cannot be due to ignorance rather than
false belief due to their anticipatory looking
(before the event occurred)
> they never see the actor’s search behavior so their response can not be due to external cues.
> use of novel stimuli rules out the use of behavior rules (i.e., the object is in the last place you saw it).
*evidence of implicit tom task passing rather
than explicit tom tasks in apes. tom is not
specific to humans.
Models (3)
Spatial Memory: > food catches retrieval accuracy (+) starvation avoidance (-) dominance > overwinter survival
Operant Learning:
> innovative problem solving
(-) responsiveness to predators and nest success is then (+) linked to recruitment to the pool of breeders
(+) nest attentiveness and the number of fledglings (+) linked to the recruitment to the pool of breeders.
General Cognitive Ability:
> innovative problem-solving speed
(+) bower quality (+) is linked to mating success which is (+) linked to reproductive success.
