<< Chapter < Page Chapter >> Page >
severity of conflict on the vertical axis, and population ratio on the horizontal axis. A scatterplot.
The relationship between population ratio (males aged 15 to 29 years per 100 males aged over 30 years) and conflict severity (death toll per million population per year) from 1980 to 1993 on a logarithmic scale. ( Adapted from Mesquida and Wiener 1995 )

severity on the vertical axis, and population ratio on the horizontal axis. A scatterplot.
The relationship between the 1989 population ratio (males aged 15 to 29 years per 100 males aged over 30 years) and severity of conflict (total death toll per million population) from 1989 to 1993 on a logarithmic scale. (Adapted from Mesquida and Wiener 1995)

How does testosterone affect aggression?

Although this chapter focuses on ultimate causes of human warfare, it is just as important to examine proximate causes in order to fully understand the nature of human aggression, such as the relationship between testosterone and aggression. Testosterone is the sex androgen believed to be responsible for masculine characteristics, and since females tend to have lower levels of testosterone as well as aggression, testosterone is assumed to have a causal relationship with aggressive behavior. In non-human animals, the hormone is known to be related to aggressiveness, and some studies have found a weak, positive relationship between testosterone levels and aggressiveness in humans as well (Book, Starzyk, and Quinsey 2001; Archer 1991). Testosterone levels have been shown to rise in males before engaging in competitive sports (Mazur and Booth 1998), and levels of testosterone can predict aggression in preschool boys (Sanchez-Martin, Fano, Ahedo, Cardas, Brain, and Azpiroz 2000). However, since studies in humans have largely been corrlational (Archer 1991), the exact nature of the relationship of testosterone in aggressive behavior in humans remains unclear.

Resource competition theory: why do males commit coalitionary violence?

The resource competition theory of coalitionary aggression posits that individual male participants involved in coalitionary acts of aggression gain fitness through an increased access to fitness-enhancing resources, as women prefer to mate with men who are able to provide themselves and potential offspring with these resources (Buss 1989). In this model, aggressive acts may increase fitness either when resources are under the control of a competitor, wherein an aggressor would increase fitness by gaining access to the resource, or when access to a resource is threatened by a competitor, wherein an aggressor avoids a fitness loss by limiting competition (Durham 1976; Buss and Shackelford 1997). Additionally, coalitions of men may also directly compete for access to women; for example, among the Yanomamo tribes have been recorded to raid neighboring groups and kidnap reproductive-aged females (Chagnon 1983 cited by Buss and Shackelford 1997).

In order to determine whether groups of males are more likely to compete over resources or females, researchers Manson and Wrangham hypothesized that when resources are easily monopolized, conflict will likely occur over these resources. However, in circumstances where essential resources are not easily monopolized, conflict will likely occur over females themselves. To ensure that resources are in fact related to reproductive fitness, the researchers also hypothesized that in situations where resources are easily monopolized, the accumulation of wealth will be associated with polygyny , whereas when resources are not easily monopolized, polygyny will correlate with other factors, such as social ranking or ability to defend family. To test this theory, the researchers analyzed the anthropological literature for ethnographic accounts of autonomous societies dependent on hunting and foraging that at least occasionally engaged in warfare. The researchers recorded whether the societies fought over resources or females, whether resources were easily monopolized, and whether polygyny and wealth were related. Results were consistent with predictions (see [link] and [link] ) (Manson and Wrangham 1991).

Questions & Answers

show that the set of all natural number form semi group under the composition of addition
Nikhil Reply
explain and give four Example hyperbolic function
Lukman Reply
_3_2_1
felecia
⅗ ⅔½
felecia
_½+⅔-¾
felecia
The denominator of a certain fraction is 9 more than the numerator. If 6 is added to both terms of the fraction, the value of the fraction becomes 2/3. Find the original fraction. 2. The sum of the least and greatest of 3 consecutive integers is 60. What are the valu
SABAL Reply
1. x + 6 2 -------------- = _ x + 9 + 6 3 x + 6 3 ----------- x -- (cross multiply) x + 15 2 3(x + 6) = 2(x + 15) 3x + 18 = 2x + 30 (-2x from both) x + 18 = 30 (-18 from both) x = 12 Test: 12 + 6 18 2 -------------- = --- = --- 12 + 9 + 6 27 3
Pawel
2. (x) + (x + 2) = 60 2x + 2 = 60 2x = 58 x = 29 29, 30, & 31
Pawel
ok
Ifeanyi
on number 2 question How did you got 2x +2
Ifeanyi
combine like terms. x + x + 2 is same as 2x + 2
Pawel
x*x=2
felecia
2+2x=
felecia
Mark and Don are planning to sell each of their marble collections at a garage sale. If Don has 1 more than 3 times the number of marbles Mark has, how many does each boy have to sell if the total number of marbles is 113?
mariel Reply
Mark = x,. Don = 3x + 1 x + 3x + 1 = 113 4x = 112, x = 28 Mark = 28, Don = 85, 28 + 85 = 113
Pawel
how do I set up the problem?
Harshika Reply
what is a solution set?
Harshika
find the subring of gaussian integers?
Rofiqul
hello, I am happy to help!
Shirley Reply
please can go further on polynomials quadratic
Abdullahi
hi mam
Mark
I need quadratic equation link to Alpa Beta
Abdullahi Reply
find the value of 2x=32
Felix Reply
divide by 2 on each side of the equal sign to solve for x
corri
X=16
Michael
Want to review on complex number 1.What are complex number 2.How to solve complex number problems.
Beyan
yes i wantt to review
Mark
use the y -intercept and slope to sketch the graph of the equation y=6x
Only Reply
how do we prove the quadratic formular
Seidu Reply
please help me prove quadratic formula
Darius
hello, if you have a question about Algebra 2. I may be able to help. I am an Algebra 2 Teacher
Shirley Reply
thank you help me with how to prove the quadratic equation
Seidu
may God blessed u for that. Please I want u to help me in sets.
Opoku
what is math number
Tric Reply
4
Trista
x-2y+3z=-3 2x-y+z=7 -x+3y-z=6
Sidiki Reply
can you teacch how to solve that🙏
Mark
Solve for the first variable in one of the equations, then substitute the result into the other equation. Point For: (6111,4111,−411)(6111,4111,-411) Equation Form: x=6111,y=4111,z=−411x=6111,y=4111,z=-411
Brenna
(61/11,41/11,−4/11)
Brenna
x=61/11 y=41/11 z=−4/11 x=61/11 y=41/11 z=-4/11
Brenna
Need help solving this problem (2/7)^-2
Simone Reply
x+2y-z=7
Sidiki
what is the coefficient of -4×
Mehri Reply
-1
Shedrak
A soccer field is a rectangle 130 meters wide and 110 meters long. The coach asks players to run from one corner to the other corner diagonally across. What is that distance, to the nearest tenths place.
Kimberly Reply
Jeannette has $5 and $10 bills in her wallet. The number of fives is three more than six times the number of tens. Let t represent the number of tens. Write an expression for the number of fives.
August Reply
What is the expressiin for seven less than four times the number of nickels
Leonardo Reply
How do i figure this problem out.
how do you translate this in Algebraic Expressions
linda Reply
why surface tension is zero at critical temperature
Shanjida
I think if critical temperature denote high temperature then a liquid stats boils that time the water stats to evaporate so some moles of h2o to up and due to high temp the bonding break they have low density so it can be a reason
s.
Need to simplify the expresin. 3/7 (x+y)-1/7 (x-1)=
Crystal Reply
. After 3 months on a diet, Lisa had lost 12% of her original weight. She lost 21 pounds. What was Lisa's original weight?
Chris Reply
Got questions? Join the online conversation and get instant answers!
Jobilize.com Reply

Get Jobilize Job Search Mobile App in your pocket Now!

Get it on Google Play




Source:  OpenStax, Mockingbird tales: readings in animal behavior. OpenStax CNX. Jan 12, 2011 Download for free at http://cnx.org/content/col11211/1.5
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Mockingbird tales: readings in animal behavior' conversation and receive update notifications?

Ask