Final answer:
The specific results of the study conducted by Dickinson & O'Connell in 1990 are not provided in the information. Instead, references to various other studies spanning different years and topics are available, suggesting that the student may be inquiring about a study related to social studies, public health, or economics.
Step-by-step explanation:
The study conducted by Dickinson & O'Connell in 1990 is not directly referenced within the information provided. However, based on the contexts given related to a range of studies from different fields such as public health, education, and economics, it seems that the student could be asking about a study related to these areas. Since Dickinson & O'Connell (1990) is not detailed among the listed references such as Eisen et al., Torchin et al., Lee et al., Ge et al., and others, including the American National Election Study in 1992, it is advisable to look for the original study by Dickinson & O'Connell as it might focus on a specific topic in social studies, public health, or economics.