Final answer:
The two key components of a 'true experiment' are random assignment and manipulation of variables, which enable causality to be established in an experiment.
Step-by-step explanation:
The two key components of a 'true experiment' as outlined in Chapter 2 of The Rubber Brain are random assignment and manipulation of variables. These elements are critical for experimental design as they allow researchers to control for lurking variables and to directly measure the effects of the independent variable on the dependent variable. By randomly assigning participants to control and experimental groups, psychologists ensure that each group is equivalent at the start of the experiment. The independent variable is then manipulated only for the experimental group to determine its causal effect on the dependent variable, while the control group does not receive this manipulation. Well-designed experiments allow researchers to make causal inferences about the relationship between independent and dependent variables.