Final answer:
Classical conditioning is the type of associative learning that explains the research on meaningful lives through systematic connections, where organisms learn to expect events that reliably occur together, such as lightning and thunder.
Step-by-step explanation:
The type of associative learning that best explains the research suggesting that people view their lives to be more meaningful when they make systematic connections between reliable stimuli is classical conditioning. This form of learning involves organisms learning to associate two events or stimuli that repeatedly occur together. For example, hearing thunder after seeing lightning makes you anticipate and react to the latter due to their consistent pairing. Similarly, when people can rely on the occurrence of certain events following specific stimuli, they find greater meaning in their lives because of the predictable nature of these associations.
Another form of associative learning is operant conditioning, where an organism learns to associate a behavior with its consequence. Positive consequences tend to increase the likelihood of repeating the behavior, contributing to a sense of reliability and meaningfulness in one's environment. Finally, observational learning adds another dimension where one learns by observing and imitating the actions of others, further enriching the tapestry of associations that give meaning to our experiences.