I draw your attention to this research paper from Professor Mike Adams from Eastern Connecticut State University titled The Dead Grandmother/Exam Syndrome, also published in The Annals of Improbable Research. In the paper, Adams investigates the phenomenon he summarizes as follows:

A student's grandmother is far more likely to die suddenly just before the student takes an exam than at any other time of the year.

He takes twenty years of historical data and confirms the existence of the phenomenon, thereby drawing attention to an important but overlooked national health problem: Increased mortality of women with grandchildren in college during the weeks leading up to exams.

  • If there is no exam imminent, the death rate is independent of how well the student is doing in class.
  • As a midterm nears, the death rate goes up by a factor of ten. As a final looms, it goes up by a factor of 19.
  • The effect is strongly dependent on how well the student is doing in class. Grandmothers of students doing poorly are at much greater risk. A grandmother of a failing student is 50 times more likely to die in the week prior to a final than a grandmother of a top student when there is no examination imminent.
  • Grandmothers are 24 times more likely to die than grandfathers.
  • The effect is independent of family size.

Adams develops theories which attempt to explain these phenomena and also has some proposals for addressing the effect.

A follow-up study by professor Lee Jussim of Rutgers University examined ways of addressing this enormous danger posed to grandmothers. In A Preliminary Report on an Intervention Designed to Reduce Grandmother Death Resulting From College Exams, Jussim found a way to save the lives of 4 out of 5 grandmothers during the lead-up to exams: Inform students that the make-up exam will be brutally difficult.

Bonus chatter: The articles are written tongue-in-cheek, but other less whimsical explanations for the observed behavior include

  • If a grandmother passes when no exam is imminent, the student will miss class without explanation.
  • Good students are less likely to ask for assistance with exams even if they lose a grandmother.
  • A student with an ill grandmother is more likely to have poor grades due to stress/worry.

Note also that the predicted grandmother popular collapse did not come to pass. One theory is that this was prevented due to another phenomenon: Grade inflation.