Psychology Unit 2 Vocab

Twins who develop from a single fertilized egg that splits into two, creating two genetically identical organisms.

Twins who develop from separate eggs. They are genetically no closer than brother and sister but share a fetal environment.

The proportion of variation among individuals that we can attribute to genes.

The shared attitudes, beliefs, norms, and behaviors of a group communicated from one generation to the next; may function to ensure a groups survival.

Understood rules for accepted and expected behavior; norms describe "proper" behavior.

A neural impulse; a brief electrical charge that travels down the axon of a neuron.

The "recharging phase" which a neuron, after firing, can generate another action potential.

The state of a neuron when it is at rest and capable of generating action potential.

The principle of stating that if a neuron fires, it always fires at the same intensity; all action potentials are the same strength.

The tiny, fluid gilled gap between the tip of the sending neuron and the receptor site on the receiving neuron. Tiny gap at this junction is called the synaptic gap or cleft.

Chemical messengers that, when released by sending a neuron, travel across the synapse and bind to the receptor sites on receiving neurons, setting up the next link in the chanin of communication within the nervous system.

A neurotransmitter that triggers muscle contraction and effects learning and memory.

A neurotransmitter that affects learning, attention, and emotions; excess dophamine activity is associated with schizophrenia.

A neurotransmitter that affects hunger, sleep, arousal, and mood. Serotonin appears in lower than normal levels in depressed persons.

Chemical messengers produced by the endoctrine glands and circulated in the blood.