Lecture 16: Everyday life Flashcards
What are the two types of pathogens?
Give examples of each
Microparasites; bacteria, protozoa and viruses.
Macroparasites; Helminths, arthropods.
Why is it bad to have an infection?
It disrupts your energy balance, the pathogen and the defence causes damage, the pathogen can induce behavioural change, they can make you more susceptible to other pathogens and it can kill you.
How do you avoid diseases?
You have developed cue detections and triggered emotional and cognitive responses.
Describe some behaviours that non-humans have to avoid microparasites
What about macroparasites?
Grooming; post-copulatory or wound cleaning, conditioned food aversions and infanticide.
Foraging away from faeces, selectively defecating, grooming, fly repelling behaviour like tail twitching and lining nests with plants that are toxic to the parasite. Some birds do anting which is when they rub their wings on ants so that they release toxins that act as insecticides.
Discuss disgust, is it cross cultural?
It’s uniquely human but is universal and has similar elicitors. Disgust is the core of the behavioural immune system.
Describe the three model structure of disgust
It involves microbes, mating and morality.
Pathogen disgust; you avoid physical contact of sources with infectious disease
Sexual disgust; you avoid sexual partners that would jeopardise reproduction and you avoid behaviours that would as well
Moral disgust; You endorse rules and coordinate moral condemnation
What are the four ways of measuring disgust sensitivity?
Scales/questionnaires
Rating images
Measuring facial expressions
Disgusting tasks followed by rating
Food disgust is part of pathogen disgust, talk about food disgust
Humans are omnivores which offers a wide range of nutrition but it means we have a greater chance of ingesting harmful or poisonous substances. So our disgust helps us create an internal code for good or bad foods. The foods that are found disgusting are culturally influenced, for example some countries eat fermented fertilised eggs. Curtis 2004 believed that disgust has evolved to protect us from disease. He did an experiment with petri dishes and found that people were more disgusted by a yellow substance with red bits in it and the blue one was the most appealing. This shows that we are programmed to be disgusted at particular things.
Describe the development of disgust
It develops during the first two years of life. Rozin did an experiment where he offered toddlers various foods. Children didn’t reject juice that had a grasshopper dipped in it or imitation poo until they were 8. Cashdan found that the first two years is the sensitive period for learning what to eat and food preferences are difficult to change after this.
Why don’t people engage in disease avoidance all the time?
It’s too costly as it would cause a lot of energy expenditure, reduce mating opportunities and reduce nutrition opportunities.
Are people that are more vulnerable to disease, more disgust sensitive?
What influences disgust sensitivity?
Does your level of disgust affect your immune system?
It has been found that women are as well as people who have been recently ill. The recently ill tend to avoid heightened or disfigured individuals. People that are more disease vulnerable have more stigma against elderly and obese people.
Fleischman 2011 found that progesterone coincides with the menstrual cycle, on the cycle days, disgust levels increase then rapidly decrease.
Yes, your disgust increases your immune response. For example, when shown a picture of a gun or someone coughing, IL-6 (an immune response/cell signalling molecule) is released a lot more in response to the coughing. It also raises your body temperature and salivary immune parameters.
Discuss sex differences in terms of sexual disgust
Women are more disgust sensitive than men in the sexual domain and overall. The effect sizes of females’ disgust compared to men; sexual disgust: 1.44, pathogen: 0.32, moral: 0.23.
Is sex riskier for males or females in terms of pathogens?
It’s riskier for females as they have a greater surface area, more trauma and more mucous membranes. Women are three times more likely to contract chlamydia. 20% of women with pelvic inflammatory disease have chronic pain.
Discuss how aroused men are less disgusted at things
When men are aroused, they’re less disgusted at having sex with: a 60 year old, a fat woman, a sweaty woman, a urinating women, an anus, an animal. Stevenson 2009 exposed men to porn and found that men rated tactile and auditory stimuli as less disgusting when aroused.
Are aroused women less disgust sensitive?
Women watched an exciting, boring or pornographic film. They then did sex related disgusting tasks like disposing of used pants and they did non-sex related disgusting tasks like sticking a needle in a cow’s eyeball. The results showed that they are slightly less disgust sensitive as more women completed the tasks when aroused. They also reported the tasks as less disgusting.
