15.2.3 The MAOA Gene

• What does the MAOA gene code for?

  Monoamine oxidase A
• High MAOA activity leads to lower levels of serotonin.
• Low MAOA activity contributes to reduced impulse control
• Which neurotransmitters does the MAOA enzyme break down?

  Serotonin, dopamine, noradrenaline
• The level of MAOA activity affects the levels of neurotransmitters, influencing aggression.
• The MAOA enzyme breaks down neurotransmitters in the brain
• Match the MAOA activity with its effect on neurotransmitter levels:

  High MAOA ↔️ Low serotonin

  Low MAOA ↔️ Increased neurotransmitters
• What is another name for the MAOA gene?

  Warrior gene
• High MAOA activity leads to lower levels of serotonin
• Individuals with low MAOA activity may react aggressively to minor frustrations.
• What are the two main variants of the MAOA gene based on enzyme activity?

  High-activity and low-activity
• Low-activity MAOA can cause reduced impulse control
• Match the MAOA variant with its effect on neurotransmitter levels:

  High-activity MAOA ↔️ Low serotonin

  Low-activity MAOA ↔️ Increased neurotransmitters
• Which study found that low-activity MAOA combined with childhood maltreatment increases aggression?

  Caspi et al. (2002)
• Low-activity MAOA combined with childhood maltreatment leads to increased aggression
• What is the impact of low MAOA activity on mood and behavior?

  Reduced impulse control
• Individuals with low MAOA activity may experience overstimulation due to higher neurotransmitter levels
• MAOA breaks down neurotransmitters such as serotonin, dopamine, and noradrenaline
• High MAOA activity is associated with low levels of serotonin, dopamine, and noradrenaline.
• Match the MAOA activity with its effect on neurotransmitter levels:

  High MAOA activity ↔️ Low neurotransmitter levels

  Low MAOA activity ↔️ High neurotransmitter levels
• Individuals with low MAOA activity may experience mood instability due to overstimulation
• What are the two main variants of the MAOA gene?

  High-activity and low-activity
• High-activity MAOA results in faster breakdown of neurotransmitters like serotonin
• Low-activity MAOA slows down the breakdown of neurotransmitters, increasing their levels.
• Arrange the following impacts of MAOA variants on aggression in order:

  1️⃣ High-activity MAOA: Low serotonin levels

  2️⃣ High-activity MAOA: Increased impulsive aggression

  3️⃣ Low-activity MAOA: Increased neurotransmitters

  4️⃣ Low-activity MAOA: Reduced impulse control
• What is one example of a behavioral trait linked to low-activity MAOA?

  Aggressive reaction to frustration
• Caspi et al. (2002) found that individuals with the low-activity MAOA gene combined with early childhood maltreatment exhibited higher levels of aggression
• The interaction between genetics and environment is crucial in determining aggressive behavior.
• What is one limitation of MAOA research related to oversimplification?

  Ignores multifactorial nature
• Genetic determinism in MAOA research implies that genes predetermine aggression
• Small sample sizes in MAOA studies can affect the reliability and generalizability of findings.