Description:
I read a story in a newspaper (yes, back when they existed) claiming that the chemical genistein, which is naturally occurring in soya, was linked to lowered sperm counts in Western males. When you read the actual study, it had been conducted on rats, and it found no link to lowered sperm counts, but there was evidence of abnormal sexual development in male rats (probably because genistein acts like oestrogen). As journalists tend to do, a study showing no link between soya and sperm counts was used as the scientific basis for an article about soya being the cause of declining sperm counts in Western males (never trust what you read). Imagine the rat study was enough for us to want to test this idea in humans. We recruit 80 males and split them into four groups that vary in the number of soya “meals” they ate per week over a year-long period (a “meal” would be a dinner containing 75 g of soya). The first group was a control and ate no soya meals (i.e., none in the whole year); the second group had one soya meal per week (that's 52 over the year); the third group had four soya meals per week (208 over the year); and the final group had seven soya meals a week (365 over the year). At the end of the year, the participants were sent away to produce some sperm that I could count (when I say “I”, I mean someone else in a laboratory as far away from me as humanly possible).

Variables:

• Soya: Number of soya meal per week (no, 1, 4 or 7 meals)
• Sperm: Sperm count (per ml)
• Ranks: Ranks according to the sperm count (Sperm)

Reference:
Field, A. P. (2017). Discovering Statistics Using IBM SPSS Statistics (5th ed.). Sage. [Fictional data set]
The data set was constructed by Andy Field who therefore owns the copyright. Andy Field generously agreed that we can include the data set in the jamovi data library. This data set is also publicly available on the website that accompanies Andy Field`s book, https://edge.sagepub.com/field5e. Without Andy Field`s explicit consent, this data set may not be distributed for commercial purposes, this data set may not be edited, and this data set may not be presented without acknowledging its source (i.e., the terms of a CC BY-NC-ND license).