Chapter 1. Paired-Samples t Test: Share and Share Alike

1.1 Paired-Samples t Test: Share and Share Alike

An old adage says that it’s better to give than to receive. But is that really true? A series of studies explored how much people enjoy receiving rewards and how much they enjoy giving them away (Aknin, Broesch, Hamlin, & Van de Vondervoort, 2015). Many studies have looked at the effects of generosity on happiness, but most were conducted in industrialized countries, primarily in North America. In contrast, Lara Aknin and her team of Canadian researchers have explored prosocial behaviors in Uganda, India, and South Africa to see if previous generosity research reflects something universal about human behavior. In one study, conducted in rural villages in the South Pacific island nation of Vanuatu, these researchers studied sharing behavior in children.

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Question 1.1

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1.2

Before we dig into the details of this study, let’s look at this particular sample. The researchers reported that 20 “children from the same small-scale, rural villages on Tanna Island in Vanuatu (14 boys, [M] = approximately 2 years and 1 month, age range 2 years 4 months–4 years 8 months) participated in this experiment. A sample size of 20 children was determined in advance, as consistent with previous research utilizing the same paradigm (Aknin et al., 2012), to provide enough statistical power to detect a medium to large effect” (Aknin et al., 2015, p. 791).

1.3

In the experiment in Vanuatu, children between the ages of 2 and 5 were introduced to a puppet named Monkey (Aknin et al., 2015). In the first phase, experimenters showed the children that the puppet enjoyed eating candy. The experimenter placed candy in a bowl with a false bottom. When the experimenter mimed the puppet eating by putting the puppet’s face in the bowl (while saying “Yum yum yum!”), the candies would fall through the false bottom. And, voilà: Monkey seemed to eat the candies!

Later, the children experienced two situations. In one situation, they were given candies by the experimenter. In a second situation, they were asked to give one of their own candies to Monkey. Experimenters recorded the children on video and later rated how happy they appeared in each condition on a scale of 1 (extremely unhappy) to 7 (extremely happy).

1.4

The researchers reported that “children displayed significantly more happiness when … giving … their own candy to Monkey (M = 5.24, SE = .18)—than when they received candies themselves (M = 4.53, SE = .23), t(16) = 3.747, p = .005, d = .83” (p. 792).

1.5

As we just saw, the researchers conducted a paired-samples t test to compare the ratings of children’s happiness when giving their own candies to Monkey versus receiving candies for themselves. Here are the results again: “Children displayed significantly more happiness when … giving … their own candy to Monkey (M = 5.24, SE = .18)—than when they received candies themselves (M = 4.53, SE = .23), t(16) = 3.747, p = .005, d = .83” (p. 792).

1.6

As we noted previously, the researchers reported that “children displayed significantly more happiness when … giving … their own candy to Monkey (M = 5.24, SE = .18)—than when they received candies themselves (M = 4.53, SE = .23), t(16) = 3.747, p = .005, d = .83” (p. 792).

1.7

As noted previously, the researchers reported that “children displayed significantly more happiness when … giving … their own candy to Monkey (M = 5.24, SE = .18)—than when they received candies themselves (M = 4.53, SE = .23), t(16) = 3.747, p = .005, d = .83” (p. 792).

1.8

image description

The bar graph shows happiness ratings for two conditions, receiving and giving. There are two vertical bars rising from the horizontal x-axis, one for receiving and one for giving. The vertical y-axis is labeled “Happiness ratings” and the tick marks range from 3.0 at the bottom to 5.5 at the top, at intervals of 0.5. The happiness rating is about 4.5 in the receiving condition and 5.1 in the giving condition.

Question 1.8

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Correct! When possible, the y-axis should start at 0 and extend to the highest possible score on the dependent variable, 7. The graph in this research report exaggerates this finding by including a range only from 3 to 5.5.

Actually, when possible, the y-axis should start at 0 and extend to the highest possible score on the dependent variable, 7. The graph in this research report exaggerates this finding by including a range only from 3 to 5.5.

1.9

image description

The bar graph shows happiness ratings for two conditions and looks nearly the same as the bar graph from the previous screen. There are two vertical bars rising from the horizontal x-axis, one for receiving and one for giving. The vertical y-axis is labeled “Happiness ratings” and the tick marks range from 0 at the bottom to 7 at the top, in intervals of 1; this range on the y-axis is the main difference between the bar graph from the previous screen and this bar graph. The happiness rating is about 4.5 in the receiving condition and 5.1 in the giving condition.

Question 1.9

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Correct! The bar for giving is higher than the one for receiving, and we know that this difference is statistically significant. So, children are happier, on average, when giving than when receiving.

Actually, the bar for giving is higher than the one for receiving, and we know that this difference is statistically significant. So, children are happier, on average, when giving than when receiving.

1.10

1.11

The researchers reported that when interpreting the results, it’s important to pay attention to cultural differences in how children understand puppets. “Although we opted to use a puppet to [have a similar research design to] previous research performed in North America (e.g., Aknin et al., 2012) in which most children are very familiar with inanimate toys and willing to treat puppets as interaction partners (Rakoczy & Tomasello, 2006), puppets do not exist in rural Tanna. Therefore, it is possible that children’s reactions were influenced by this novel experience” (Aknin et al., 2015, p. 793).

1.12

The bottom line: When it comes to sharing, it really does seem to be better to give than to receive—whether or not you’re from Vanuatu.

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