Do sweet flavors put us in a happier mood? Do bitter flavors go with being judgmental? A Washington Post journalist pulled together several studies of human taste and human judgment. Together, they provide excellent practice for discriminating between correlational and experimental studies.
Here's study #1:
About 30 percent of people can detect the bitter taste of a rather disgusting substance — its scientific name is 6-n-propylthiouracil — even in very low concentrations, and in general these people find bitter taste in foods stronger and less pleasant than other people do. This sensitivity is genetically based, research has found, and is related in the number of mushroomlike structures on the tongue called fungiform papillae, on which taste buds are perched.,,, In a 2014 experiment, German and American psychologists showed that, like bitter-sensitive rats, bitter-sensitive people tended to be jumpy, meaning they reacted more strongly than other folks when exposed to a loud noise.
1a) What are the variables in this study? For each, is it manipulated or measured?
1b) Does this study appear to be correlational or experimental?
1c) Sketch a graph of the results they have described (Would a scatterplot or a bar graph be best?) Label your axes carefully.
1d) If this is an experiment, what are the IVs and DVs? What kind does it appear to be: Posttest only? Prettest posttest? Repeated measures? Concurrent measures?
Here's study #2
A study published in the journal Appetite in January suggests, for example, that there is a link between enjoyment of bitter taste and antisocial personality traits. In that study, close to 1,000 Americans were given standard personality and taste-preference questionnaires. People who enjoyed foods with bitter notes — such as grapefruit, tonic water, coffee and radishes — were more likely to admit that they enjoyed tormenting people or that they tend to manipulate others to get their way.
2a) What are the variables in this study? For each, is it manipulated or measured?
2b) Does this study appear to be correlational or experimental?
2c) Sketch a graph of the results they have described (Would a scatterplot or a bar graph be best?) Label your axes carefully.
2d) If this is an experiment, what are the IVs and DVs? What kind does it appear to be: Posttest only? Prettest posttest? Repeated measures? Concurrent measures?
Study #3:
Imagine you’ve heard of a politician accepting bribes or of a student stealing library books: How harshly would you judge the offender? According to a 2011 study, that may depend on what you’ve just tasted: Volunteers who had just [been randomly assigned to] take a gulp of an extremely bitter herbal tonic judged various moral transgressions as far more serious than people drinking nothing but water.
3a) What are the variables in this study? For each, is it manipulated or measured?
3b) Does this study appear to be correlational or experimental?
3c) Sketch a graph of the results they have described (Would a scatterplot or a bar graph be best?) Label your axes carefully.
3d) If this is an experiment, what are the IVs and DVs? What kind does it appear to be: Posttest only? Prettest posttest? Repeated measures? Concurrent measures?
Study #4
In 2014 Sagioglou and a colleague conducted several experiments in which they showed that tasting bitterness leads to aggression. An example: After [randomly assigning them] to taste either grapefruit juice or water, students were asked to assess how they’d feel in certain situations — say, if someone kicked the back of their chair repeatedly at the movies. Results showed that the bitter-tasters would react with more hostility and irritation — imagining themselves threatening the annoying moviegoer if he didn’t stop — while water drinkers just ignored the bothersome behavior.
4a) What are the variables in this study? For each, is it manipulated or measured?
4b) Does this study appear to be correlational or experimental? (The journalist calls them experiments–are they really?)
4c) Sketch a graph of the results they have described (Would a scatterplot or a bar graph be best?) Label your axes carefully.
4d) If this is an experiment, what are the IVs and DVs? What kind does it appear to be: Posttest only? Prettest posttest? Repeated measures? Concurrent measures?
Study #5
A 2015 study suggested that the reverse is also true: Men who were happy because their hockey team had just won a game rated a lemon-lime sorbet as sweeter and less sour than men who had cheered for a losing team.
5a) What are the variables in this study? For each, is it manipulated or measured?
5b) Does this study appear to be correlational or experimental? (or maybe quasi-experimental?)
5c) Sketch a graph of the results they have described (Would a scatterplot or a bar graph be best?) Label your axes carefully.
5d) If this is an experiment, what are the IVs and DVs? What kind does it appear to be: Posttest only? Prettest posttest? Repeated measures? Concurrent measures?