File Tools View B summary math assignment . Saved to this PC . X Background: shaped like the hinderer in the video, 14 of the 16 infants chose the helper over the hin- Researchers in the Psychology Department at Yale University investigate the development derer. The Yale researchers concluded that infants prefer the helper toy and that this im- of moral, social and cognitive behaviors in infants as a way of gaining insight into the un- plies that infants have an innate ability to evaluate individuals based on how they interact derpinnings of human behavior. with another individual. But wait...how do we know that infants really prefer the helper toy when we only have results In an introduction to a famous study published in Nature in 2007, Yale researchers wrote, from a single sample? Could these results occur if infants are just arbitrarily choosing a toy? 'The capacity to evaluate other people is essential for navigating the social world. Humans What's the probability that this happens? We will conduct a simulation to answer these ques- must be able to assess the actions and intentions of the people around them, and make ac- tions to see if the simulation supports the conclusions reached by the Yale researchers. curate decisions about who is friend and who is foe, who is an appropriate social partner and who is not."1 1 http://www.nature.comature/journal/v4507169/fullature06288.html The following summary of this study is from Science Daily2 2 http://www.sciencedaily.com/releases/2012/08/120815093230.htm 'The 2007 study by Yale University researchers provided the first evidence that 6- and 10- month-old infants could assess individuals based on their behavior towards others, show- ing a preference for those who helped rather than hindered another individual. ... In the original experiment, infants watched a wooden toy (i.e., the "climber") attempt to climb a hill. They viewed two social interactions; one in which a "helper" toy nudged the climber up O the hill, and another in which a "hinderer" toy nudged the climber down the hill. After viewing these two scenarios, the infants were presented with a tray; on one side of the tray was the helper and on the other side was the hinderer. Amazingly, the majority of infants picked the helper over the hinderer. To further elucidate infants' moral reasoning abilities, a "neutral" toy (i.e., a toy that neither helped nor hindered) was pitted against the helper or hinderer. When the neutral character was paired with the helper, the infants pre- ferred the helper; when paired with the hinderer, they preferred the neutral character. ... The paper concluded that the experiments show that infants can evaluate individuals based on how they interact with another individual, and that their ability to do this is 'universal and unlearned'." Click here to see some discussion and video of the experiment. In the Yale study, the infants watched the videos several times. Afterwards, when the in- fants were shown a tray with two pieces of wood, one shaped like the helper and the other Screens 1-2 of 6 Focus 1409 Search 40" W 7:51 AM 11/30/2022File Tools View B summary math assignment . Saved to this PC . X Simulation the sampling distribution using Statkey The Statkey applet simulates sample proportions by having the computer flip a coin to choose between two levels of a categorical variable. It makes sense to use a coin flip in the simulation because in the experiment the infants had a choice between two toys (helper 1) Here are the results from one sample of and hinderer). a) What is the sample proportion for the 1 ctured? Let's assume that the population proportion reflects that infants do not have a preference. If this is true, then their choices can be simulated with a coin flip where the probability of There are 10 heads so, 10/16= 0.625 heads is 0.5. In the simulation each coin toss will represent one infant's choice. A head tells 0.625 proportion of infants preferred the toys us that the infant chose the helper toy. A tail tells us that the infant chose the hinderer toy. b) Write a sentence to explain the meaning of this sample proportion in Population proportion: 0.5 (Because we are assuming that the infants are arbitrarily the context of infants, toys and the variable in this research question. choosing, in the long run we expect 50% to choose the helper toy.) There are 6 tails illustrated in the sample proportion so, Sample size: 16 There are 16 infants in each sample. 6/16= 0.375 The proportion of infants using toys is 0.375 2) Simulate the sampling distribution in StatKey. Copy and paste a picture of the distribu- C tion here using 15,000-20,000 samples. Starkey Sampling Distribution emptng Detales of Proportion a) What does each dot repre- sent? Include all details. Each dot represents one infant b) Give an accurate label for the x-axis in terms of babies and toy preference Proportion of infants with toy preference c) Explain if a Normal model is a good fit for this distribution. Screens 3-4 of 6 Focus 1409 Search 1 S HQ E L V J DOW 7:51 AM 11/30/2022File Tools View B summary math assignment . Saved to this PC . X Toy Helper or Toy Hinderer 5. What type of data analysis? 6. Explain how you know this is an experiment. Because there were some variables that were controlled during the experiment like for ex- ample 7. Using the video clip, list two confounding variables they controlled for and describe how Questions about making an inference based on a distribution of sample proportions they controlled it. 3) In the Yale experiment, 14 out of 16 infants chose the helper toy. Give the sample pro- 4) Researchers in the Department of Psychology at the University of Otago in New Zealand have portion for the Yale experiment with the correct symbol. challenged the findings from the Yale study. Read the short article from Science Daily and de- scribe the confounding variables that are the focus of the New Zealand critique. Summarize what a) Is 14 out of 16 unusual in a random sample if we assume p=0.5 and n=16? Explain the New Zealand researchers did to investigate the effects of these confounding factors. how you know using your screenshot of your Statkey simulation. http://www.sciencedaily.com/releases/2012/08/120815093230.htm New research from the University of Otago suggests that infants are not morally compass, b) Give the simplified description of the simulated distribution. and may simply prefer interesting and attention grabbing events, rather than evaluating indi- 4 viduals based on their social interactions with others. c) What is the probability that in a random sample of 16 infants, 14 or more will choose the helper toy? Use probability notation. End of document The Yale researchers claim that infants recognize, and make judgments about, other individu- als based on how they interact with each other. To show this, their experiment must pro- duce strong evidence that the infants are not arbitrarily picking one toy over the other. d) Explain if their experiment provides strong evidence in support of their claim that in- fants have a preference for the helper. Review questions. 1. What is the individual? An infant 2. What is the sample? 16 infants 3. What is the intended population? All infants 4. What is the variable? Type? units/categories? Which toy will the infant choose? Categorical Screens 5-6 of 6 " Focus 1409 Search 40" MO B L O J DOW 7:51 AM 11/30/2022