What does a higher correlation coefficient mean?

Definition of correlation

A correlation measures the strength of a statistical relationship between two variables. With a positive correlation, “the more variable A… the more variable B” or vice versa, with a negative correlation “the more variable A… the less variable B” or vice versa. There is a negative correlation between the variable “current age” and “remaining life expectancy”. The higher a person's current age, the lower the average remaining life expectancy. Correlations are always undirected, that is, they contain no information about which variable causes another - both variables are equal. The strength of the statistical relationship is expressed using the correlation coefficient, which lies between -1 and +1. The type of a directed relationship is described by regression.

Correlations are an indication but not a proof of causalities, i.e. proven relationships between causes and effects. An example: The fact that older people more often own expensive jewelry than young people is not necessarily due to the number of years of life, taste or interests of age - a simple connection with the higher income that older people have on average would also be possible . See also autocorrelation and spurious correlation.

Please note that the individual definitions in our statistics lexicon are simplified explanations. The aim here is to bring the individual terms closer to the broadest possible user group. In this respect, it is possible that individual definitions do not fully correspond to scientific standards.