Smoking addiction genetics and initiation

Initiation

The initial point where someone develops an interest in an addictive behaviour and starts the process of addiction

Maintenance

Where the 'user' actively enjoys and chooses to regulary continue the addictive behaviour

Relapse

Where the individual has stopped the addictive behaviour, but then spontaneously starts again

Genetics

Units of information that are inherited from parents. They control or influence, characteristics such as risk of mental health disorders, personality and sexual development

Heredity

The passing of characteristics from one generation to the next through genes

How many pairs of chromosomes are we typically born with

23 inherited from their birth parents

What is the influence of genes

The genetic makeup of-up of an individual, which occurs at conception and provides the genetic code for how that individual will develop e.g. their hair or eye colour. Everyone has a unique gene type except for identical twins

When are the characteristics (physical, behavioural, psychological) of an individual produced

When their genotype interacts with the environment

What does our genotypes dictate

The maximum height a person can reach based on the height of your mother and father

What affect our genotypes

Environmental factors like nutrition can affect how likely they are to reach that height

What is the phenotype of their height

The actual height they become, not their genetic potential

What is the concordance rate in twins

The presence of the same trait (addiction) in both members of a pair of twins

What does research on addiction and genes say

-genes may be a risk factor nicotine addiction

-studies suggest that there is not 1 single gene that causes smoking addiction, but there might be many involved

-the genes associated with smoking addiction affect the chemicals in our brain that respond to nicotine in the blood

-family and twin studies have shown that smoking may run in families, which could be the result of shared genes

Evidence from studies

Carmelli et al (1991)

Vine et al (2005)

What did carmelli et al (1991) find

That in male twin pairs there was a higher concordance rate for smoking in MZ twins (100% same genes) than for DZ twins (50% same genes), suggesting that genes may be involved in developing an addiction to smoking

What did vine et al (2005) find

By investigating the heritability of smoking initiation and nicotine dependence in pairs of twins she found that genetic factors do contribute to both the initiation of smoking and dependence on nicotine and that they share a relationship with each other

Strength of both researches

Practical benefits: has found that smoking initiation is not inevitable and therefore steps can be taken to make addiction less likely. Interventions can be put in place to help parents identify and modify environmental factors that may lead to smoking initiation. Has wider benefits to society

Weakness of both researches

Has focussed on using a self report method. Participants were asked to complete a rating scale in answer to questions about how difficult it was to stop smoking. Many of the responses could have demonstrated social desirability bias

Another problem in the researches

Twin research suggests that people may inherit genes making them more likely to become addicted to nicotine however many of these twins will have shared the same environment growing up meaning their addiction could have had the same environmental cause rather than being affected by genetics