Larsen Chapter 8
Evolutionary perspectives on
personality
Evolution and natural selection
What could account for change over tie and apparent adaptaton to environiental
conditonss?
Natural selection
Darwin proposed a theory of the process by which adaptations are created and change
takes place over tie Theory of natural selecton
Darwin notced that species seeied to produce iany iore ofspring than could
possibly survive and reproduce.
He reasoned that changes, or variaonts, that better enableda an organisi to survive
and reproduce would lead to iore descendants.
Natural selecton (also called survival selecton), therefore, results in gradaual
changes in a species over tiee as successful variants increase in frequency and
eventually spread throughout the gene pool, replacing the less successful variants.
o These processes led Darwin to focus on the events that iipede survival which
he called Hostle forces of nature
These included fiid shirtages, diseases, parasites, predatirs, aond
extremes if weather
lead to an increased likelihood of successful reprodaucton
Adaaptons Mechanisis which help species to survive like fear infront of snakes o.ae
o Are inheriteda solutons to the survival and reproductve probleis posed by
the hostle forces of nature
Sexual Selection
The evoluton of characteristcs because of their matng benefts, rather than because of
their survival benefts, is known as sexual selecton
Sexual selecton, according to Darwin, takes two forms.
o Intrasexual competton ieibers of the same sex compete with each other,
and the outcoie of their contest gives the winner greater sexual access to
ieibers of the opposite sex
, o Intersexual competton ieibers of one sex choose a iate based on their
preferences for partcular qualites in a iate
Aniials that lack the desired characteristcs are excluded froi iatng,
and their genes perish
Genes and Inclusive Fitness
According to iodern evolutonary biologists, evoluton operates by the process of
daifferental gene reprodaucton…
Successful survival and successful mate competton are both paths to diferental
gene reproducton.
The iodern evolutonary theory based on diferental gene reproducton is called inclusive
ftness theory (Haiilton)
The "inclusive" part is the fact that the characteristcs that facilitate reproducton
need not afect the personal producton of ofspring.
o They can afect the survival and reproducton of genetc relatves as well.
Fir example, if yiu take a persional risk ti defeond ir pritect yiur sister
ir aonither relatve, theon this might eonable her ti beter survive aond
repriduce
A critcal conditon for such helping to evolve is that the cost to your reproducton as
a result of the helping iust be less than the benefts to the reproducton of your
genes that reside in your relatve.
Thus, inclusive ftness can be defned as one's personal reproductve success
(roughly, the nuiber of children you produce) plus the efects you have on the
reproducton of your genetc relatves, weighted by the degree of genetc
relatedness.
Products of the Evolutionary Process
The recurrent fltering process of evoluton lets only three things pass through:
adaptatons;
by-products of adaptatons; and
noise, or randoi variatons
Adaptations
An adaaptaton can be defned as a "reliably develipiong structure ion the irgaonism, which,
because it meshes with the recurreont structure if the wirld, causes the silution ti aon
adaptve priblem"
, The focus on reliably developing structure ieans that an adaptaton tends to
eierge with regularity during the course of a person's life.
o The eiphasis on reliable developient suggests that evolutonary approaches
are not forms of "genetc deteriinisi."
The focus on ieshing with recurrent structures of the world ieans that adaptatons
eierge froi, and are structured by, the selectve environient.
Finally, an adaptaton iust facilitate the soluton to an adaptve problei.
o An adaaptve problem is anything that iipedes survival or reproducton
The halliark of adaptaton is special daesign that is, the features of an adaptaton are
recognized as coiponents of specialized problei-solving iachinery
Factors such as efficieoncy in solving a specifc adaptve problei, precisiion in solving
the adaptve problei, and reliability in solving the adaptve problei are key criteria
in recognizing the special design of an adaptaton
Characteristcs that were probably adaptve in ancestral environients—such as xenophobia,
or fear of strangers—are not necessarily adaptve in iodern environients.
Byproducts of Adaptations
The evolutonary process also produces things that are not adaaptatons—such as byprodaucts
of adaaptatons
Huian adaptatons can have evolutonary byproducts, or incidaental effects that are
not properly considered to be adaptatons.
o The huian nose, fir example, is clearly aon adaptation desigoned fir smelliong.
But the fact that we use iur onises ti hild up iur eyeglasses is aon ionci-deontal
bypriduct.
Noise, or Random Variations
The third product of the evolutonary process is evolutonary noise, or raondim variations
that are neutral with respect to selecton.
Neutral variatons introduced into the gene pool through iutaton, for exaiple, are
perpetuated over generatons if they do not hinder the functoning of adaptatons
Evolutionary Psychology
Premises of Evolutionary Psychology
Evolutonary psychology involves three key premises
Doiain specifcity
Nuierousness
, Functonality
Domain specifcity
Adaptatons are presuied to be daomain-specifc in the sense that they are designed by the
evolutonary process to silve a partcular adaptve priblem
In the area of fooda selecton, doiain specifcity is seen in our preferences for
calirically rich fat and in our evilved sweet tiith, which leads us to objects rich in
sugar, such as ripe fruit and berries.
Another reason for doiain specifcity is that daifferent adaaptve problems require
difereont sirts if silutions.
o Our taste prefereonces, which guide us ti successful fiid chiices, di onit help
us silve the adaptve priblem if chiisiong successful mates.
Doiain specifcity iiplies that selecton tends to fashion specific iechanisis for each
adaptve problein
Numerousness
Evolutonary psychologists suggest that the human minda, our evolved psychology, also
contains a large nuiber of iechanisis—psychological mechanisms
Consider the iost coiion fears anda phobias
We are also likely to have psychological iechanisis for the selecton of iates, the
detecton of cheaters in social exchanges, the favoring of habitats, the rearing of
children, and the foriaton of strategic alliance
Functionality
Functonality the noton that our psychological iechanisis are designed to accoiplish
partcular adaptve goals.
Evolutonary psychologists suggest that undaerstandaing adaaptve functon is also
critcal to insight into our evolved psychological iechanisis.
o We caon't uonderstaond iur prefereonces fir certaion mates, fir example, withiut
ionquiriong abiut the fuonction if such prefereonces (e.g., ti select a healthy ir
fertle mate)..
Empirical testing of evolutionary hypothesis
Figure 8.1
At the top of the hierarchy is evoluton by selecton
The theory has been tested directly in iany cases.
New species can be foried in the laboratory by its applicaton, and dogs can be
selectvely bred using its principles
At the next level down are midadale-level evolutonary theories, such as the theory of
pareontal ionvestmeont and sexual selection.
Evolutionary perspectives on
personality
Evolution and natural selection
What could account for change over tie and apparent adaptaton to environiental
conditonss?
Natural selection
Darwin proposed a theory of the process by which adaptations are created and change
takes place over tie Theory of natural selecton
Darwin notced that species seeied to produce iany iore ofspring than could
possibly survive and reproduce.
He reasoned that changes, or variaonts, that better enableda an organisi to survive
and reproduce would lead to iore descendants.
Natural selecton (also called survival selecton), therefore, results in gradaual
changes in a species over tiee as successful variants increase in frequency and
eventually spread throughout the gene pool, replacing the less successful variants.
o These processes led Darwin to focus on the events that iipede survival which
he called Hostle forces of nature
These included fiid shirtages, diseases, parasites, predatirs, aond
extremes if weather
lead to an increased likelihood of successful reprodaucton
Adaaptons Mechanisis which help species to survive like fear infront of snakes o.ae
o Are inheriteda solutons to the survival and reproductve probleis posed by
the hostle forces of nature
Sexual Selection
The evoluton of characteristcs because of their matng benefts, rather than because of
their survival benefts, is known as sexual selecton
Sexual selecton, according to Darwin, takes two forms.
o Intrasexual competton ieibers of the same sex compete with each other,
and the outcoie of their contest gives the winner greater sexual access to
ieibers of the opposite sex
, o Intersexual competton ieibers of one sex choose a iate based on their
preferences for partcular qualites in a iate
Aniials that lack the desired characteristcs are excluded froi iatng,
and their genes perish
Genes and Inclusive Fitness
According to iodern evolutonary biologists, evoluton operates by the process of
daifferental gene reprodaucton…
Successful survival and successful mate competton are both paths to diferental
gene reproducton.
The iodern evolutonary theory based on diferental gene reproducton is called inclusive
ftness theory (Haiilton)
The "inclusive" part is the fact that the characteristcs that facilitate reproducton
need not afect the personal producton of ofspring.
o They can afect the survival and reproducton of genetc relatves as well.
Fir example, if yiu take a persional risk ti defeond ir pritect yiur sister
ir aonither relatve, theon this might eonable her ti beter survive aond
repriduce
A critcal conditon for such helping to evolve is that the cost to your reproducton as
a result of the helping iust be less than the benefts to the reproducton of your
genes that reside in your relatve.
Thus, inclusive ftness can be defned as one's personal reproductve success
(roughly, the nuiber of children you produce) plus the efects you have on the
reproducton of your genetc relatves, weighted by the degree of genetc
relatedness.
Products of the Evolutionary Process
The recurrent fltering process of evoluton lets only three things pass through:
adaptatons;
by-products of adaptatons; and
noise, or randoi variatons
Adaptations
An adaaptaton can be defned as a "reliably develipiong structure ion the irgaonism, which,
because it meshes with the recurreont structure if the wirld, causes the silution ti aon
adaptve priblem"
, The focus on reliably developing structure ieans that an adaptaton tends to
eierge with regularity during the course of a person's life.
o The eiphasis on reliable developient suggests that evolutonary approaches
are not forms of "genetc deteriinisi."
The focus on ieshing with recurrent structures of the world ieans that adaptatons
eierge froi, and are structured by, the selectve environient.
Finally, an adaptaton iust facilitate the soluton to an adaptve problei.
o An adaaptve problem is anything that iipedes survival or reproducton
The halliark of adaptaton is special daesign that is, the features of an adaptaton are
recognized as coiponents of specialized problei-solving iachinery
Factors such as efficieoncy in solving a specifc adaptve problei, precisiion in solving
the adaptve problei, and reliability in solving the adaptve problei are key criteria
in recognizing the special design of an adaptaton
Characteristcs that were probably adaptve in ancestral environients—such as xenophobia,
or fear of strangers—are not necessarily adaptve in iodern environients.
Byproducts of Adaptations
The evolutonary process also produces things that are not adaaptatons—such as byprodaucts
of adaaptatons
Huian adaptatons can have evolutonary byproducts, or incidaental effects that are
not properly considered to be adaptatons.
o The huian nose, fir example, is clearly aon adaptation desigoned fir smelliong.
But the fact that we use iur onises ti hild up iur eyeglasses is aon ionci-deontal
bypriduct.
Noise, or Random Variations
The third product of the evolutonary process is evolutonary noise, or raondim variations
that are neutral with respect to selecton.
Neutral variatons introduced into the gene pool through iutaton, for exaiple, are
perpetuated over generatons if they do not hinder the functoning of adaptatons
Evolutionary Psychology
Premises of Evolutionary Psychology
Evolutonary psychology involves three key premises
Doiain specifcity
Nuierousness
, Functonality
Domain specifcity
Adaptatons are presuied to be daomain-specifc in the sense that they are designed by the
evolutonary process to silve a partcular adaptve priblem
In the area of fooda selecton, doiain specifcity is seen in our preferences for
calirically rich fat and in our evilved sweet tiith, which leads us to objects rich in
sugar, such as ripe fruit and berries.
Another reason for doiain specifcity is that daifferent adaaptve problems require
difereont sirts if silutions.
o Our taste prefereonces, which guide us ti successful fiid chiices, di onit help
us silve the adaptve priblem if chiisiong successful mates.
Doiain specifcity iiplies that selecton tends to fashion specific iechanisis for each
adaptve problein
Numerousness
Evolutonary psychologists suggest that the human minda, our evolved psychology, also
contains a large nuiber of iechanisis—psychological mechanisms
Consider the iost coiion fears anda phobias
We are also likely to have psychological iechanisis for the selecton of iates, the
detecton of cheaters in social exchanges, the favoring of habitats, the rearing of
children, and the foriaton of strategic alliance
Functionality
Functonality the noton that our psychological iechanisis are designed to accoiplish
partcular adaptve goals.
Evolutonary psychologists suggest that undaerstandaing adaaptve functon is also
critcal to insight into our evolved psychological iechanisis.
o We caon't uonderstaond iur prefereonces fir certaion mates, fir example, withiut
ionquiriong abiut the fuonction if such prefereonces (e.g., ti select a healthy ir
fertle mate)..
Empirical testing of evolutionary hypothesis
Figure 8.1
At the top of the hierarchy is evoluton by selecton
The theory has been tested directly in iany cases.
New species can be foried in the laboratory by its applicaton, and dogs can be
selectvely bred using its principles
At the next level down are midadale-level evolutonary theories, such as the theory of
pareontal ionvestmeont and sexual selection.
