Ever thought that older people who always get cranky, grumpy and are permanently irascible may just be smarter and have an above average IQ? Well, if you just thought to blame strange and erratic behavior on old age, it is time you found out that disagreeable temper of elders may be the main sign of high intelligence. A new research suggests that those always moody, odd and petulant grandmas and grandpas are smarter than agreeable older siblings.

Scientists at Morgan State Institute in Baltimore suggested that older individuals with superior intelligence are more likely to have a disagreeable behavior. "It appears that at younger ages, openness to experience is the most important personality factor correlating with the attainment of facts, vocabulary, and book learning. But when we get older - and this hasn't been found before - it appears that openness to experience is no longer as important, and what is important is a disagreeable nature," pointed out study co-author Jacqueline Bichsel, associate Professor of Psychology the University in Baltimore.

In order to prove that grumpy elders may just be smarter than average people of their age, researchers investigated a group of 381 adults with age ranging from 19 to 89. The individuals had various degrees of education, from high school degrees to graduate school. 246 adults participating in the study were over 60. This group was further split into two smaller groups - one group included over 60s with cognitive abilities similar to those of younger people in the study and the other group consisted in older individuals with cognitive abilities superior to all the rest, both young and old.

The older people in the superior intelligence group achieved the best results at cognitive tests and they also proved to have a more disagreeable behavior than all the others volunteers. This is how researchers came to the conclusion that high cognitive skills are negatively related to agreeableness and friendliness.

"So, you don't necessarily need to get on cranky grandma and grandpa. It may be good for them to be a little argumentative, and it may show that they are retaining a high cognitive capacity," commented Professor Bichsel.