In a study reported in the November 2007 issue of Nature, researchers investigated whether infants take into account an individual's actions towards others in evaluating that individual as appealing or aversive, perhaps laying the foundation for social interaction (Hamlin, Wynn, and Bloom, 2007). In other words, do children who aren't even yet talking still form impressions as to someone's friendliness based on their actions? In one component of the study, 10-month-old infants were shown a climber character (a piece of wood with googly eyes glued onto it) that could not make it up a hill in two tries. Then the infants were shown two scenarios for the climber's next try, one where the climber was pushed to the top of the hill by another character (the helper toy) and one where the climber was pushed back down the hill by another character (the hinderer toy). The infant was alternately shown these two scenarios several times. Then the child was presented with both pieces of wood (the helper and the hinderer characters) and asked to pick one to play with.
One important design consideration to keep in mind is that in order to equalize potential influencing factors such as shape, color, and position, the researchers varied the colors and shapes of the wooden characters and even on which side the toys were presented to the infants. The researchers found that 14 of the 16 infants chose the helper over the hinderer.
Identify the explanatory and response variables in this study.
The explanatory variable is the choice of helper/hinderer by the infant. The response variable is the interaction of the characters.
Question 2. Choose the best answer.
Using the bar graph below for the frequencies of X values, determine the probability Pr(15 < X < 19). The frequency for each bar is given at the top of the bar. There are 100 observations recorded. However, because of how the data is displayed, sometimes there are bars that do not show up in the bar graph. If your answer is off by 0.01 from one of the options, this is most likely why. You may wish to pan and zoom to make sure you can see the locations of the intervals.
Pr(15 < X < 19) = 0.57.
Pr(15 < X < 19) = 0.48.
Pr(15 < X < 19) > 0.72.
Pr(15 < X < 19) < 0.63.
