Bloa Theories And Concepts

Sexual selection is the process by which characteristics are passed on to the next generation (through genetic inheritance) because they attract the opposite sex.

One sex competes with other same sex members for access to opposite sex. Competition can happen through aggression, as when two reindeer fight with each other and the winner gets to mate with the does. When successful the winning males are able to mate and pass on their genes resulting in the desirable traits to be passed onto the next generation.

This refers to the specific traits that attract the opposite sex being passed on to future generations. For example if being red-haired attracts the most females, red-haired men will have more offspring, the genes for red hair are passed on to these offspring, and over time (and many generations) human males will be more red-headed. The preferences of one sex, therefore, determine the areas in which the other sex must compete. These ‘sexy’ traits will be passed on to offspring.

According to Parental Investment theory, men and women want different things from a sexual partner because men and women have very different reproductive systems. Because men stay fertile until very old age, can father an almost unlimited number of offspring,may invest very little in the fathering of each offspring, men will prefer to have sex with many women and will seek women who are young and pretty (which indicates fertility). Meanwhile, women are fertile for only a short period of time (about 30-35 years), can have a very limited number of offspring, because of pregnancy, child-birth and breastfeeding invest very much in the production of each offspring. Therefore, women are more likely to be very selective about the males they want to have sex with, and will seek out partners who can (and want to) provide the resources needed for the woman and offspring.

Because each sexual intercourse may be very costly for the woman, but not for the man, Parental Investment theory suggests that men are more willing to participate in casual sex, while women are more selective and want sex to be within a long-term commitment. This hypothesis was tested by Clark & Hatfield (1989) in a classic and often cited study, which however has been severely criticized from many perspectives.

As women have an obligatory biological investment in their children, they would be expected to be very particular about their choice of mate. They would be attracted to males who are able to invest and provide, able to physically protect her and her children and show promise as a good parent. Meanwhile, men are expected to favour women who show signs of fertility. This was tested by Buss (1990) in a cross-cultural study of 37 cultures. However, that study has received criticisms from researchers in the socio-cultural level of analysis, because it is likely that all the cultures studied by Buss were male-dominated and gave men more power in the political and financial spheres of society.

All mental processes and behaviors are products of the activity of the nervous and hormone system.

- The Fischer study

Research done on non-human animals increases our understanding of human behavior.

- The Meany 2001

Patterns of behavior can be inherited.

-The Bouchard study

Patterns of behavior are influenced by evolutionary processes.

-the Buss study

Neurotransmission is the process of signaling neurotransmitters to be released from a neuron and go bind to a receptor of a different neuron.

A hormone which functions as a chemical neurotransmitter in the brain's nervous system. It also acts as a regulator of the reward system. After a task is completed, it is released, which prompts feelings of happiness, love, and euphoria.

The neuron is a cell which is located throughout the brain. It is responsible for the receiving and transmitting of electrical and chemical impulses, to and from other neurons, which together make up the network of nerves. There are approximately 100 billion neurons in the brain, and in total around 100 trillion connections.

GABA is a chemical messenger that is widely distributed in the brain. GABA's naturalfunction is to reduce the activity of the neurons to which it binds.

(see Meany)

Used for recording the brain activity, structure or function through various technologies such as the EEG, the CT scan, the PET, fMRI, and SPECT.

Researchers gain data from subjects who has already been shaped by factors such as nature or society. The researcher does not control any variables and only measures the variables of an event.

Researcher controls the independent variable: either by assigning participants to the different conditions (independent-group design) or by controlling the order of the conditions (repeated measures design)

EEG is a brain imaging technology that is either in the form of a cap or a helmet that has electrodes attached to specific places. These electrodes then detect changes in electrical activity below them. The EEG produces a graphical representation from each electrode. This is often used to study sleep, which would require the participant to spend a night wired up to the EEG helmet.

Con of using an EEG is that it only provides information on what happens on the surface of the brain and not really give insight on brain localization, hence it is not enough to make strong conclusions on the brain activity.

The CT scanner is a combination of computer and x-ray technology. CT scan can show the brain at any depth and hence are extremely useful for showing structural changes in the brain (f.eg. a brain tumor). However it cannot capture images of brain activity due to its structural images.

MRI is a technology based on the discovery that when the body is exposed to strong magnetic field, the protons in the water inside the body change their alignment. When a magnetic field is used in conjunction with radio frequency fields, the alignment of the hydrogen atoms is changed in a way that the scanner can detect it. The signal from the scanner is then translated into a visual representation of the area of the body being studied.

There is a danger to exposing some individuals to magnetism if their bodies contain any metal (f.eg. due to surgery, metal screws for broken bones). Mostly however MRI is preferred over CT as the exposure to X-ray might be a concern to some.

This is a modification of the regular MRI technique. It takes advantage of the fact that when neurons in a particular region are active, more blood is sent to that region. It maps metabolic changes that indicate brain activity and hence provide with accurate results with brain activity when certain thoughts or emotions occur.

It is also more flexible than the regular MRI, as it is able to provide dynamic rather than static information. It is also more precise than PET scan.

This technology requires the injection of radioactive substance into the participant. Usually this is a form of sugar that produces gamma rays as it is metabolized by the brain. This technology relies on the knowledge that parts of the brain will metabolize the sugar at different rates according to whether they are more or less active. The gamma rays can be detected by the machine in which the person is placed in.

It is good for showing dynamic image of activity, but it is much less precise than the fMRI.