I can start with something like this:
Peer effect is an important component in determinating a learner outcomes. A typical student learns from discussions with his peers and can possibly be affected by their personality and attitude towards learning. Peer students can also be motivated by working together. It is well established that the quality of peers could affect a wide range of outcomes from school performance to health conditions, or even juvenile criminal behaviour. Scientists have investigated in the peer effects for a variety of peers include proximity based peers such as schoolmates (Evans et al. (1992)), roommates (Sacerdote (2001),Hoel et al. (2005)), classmates (Ammermueller and Pischke (2009)), or linkage based peer, such as friendship, Cooley(2009),Bramoull´e et al. (2009)). The existing literature has focused on the peer effect of friendship largely because of the limited availability of data. One available source is the friendship data in The National Longitudinal Study of Adolescent Health (Add Health). Moreover, for some choices of peers, selective problems are of particular concern. Evans et al. (1992) hint at the importance of individual choices of peer groups in peer effect estimation. While exogenous random assignment experiment could exist for some peer group formation such as randomly assigned college roommates. For most peer group formation such as by means of network of friendship, such random assignment is impossible. As a result, most peer effect estimations make use of exogenously assigned peers or analyze outcomes for which the selection problem of peer types is not a key issue(e.g. health outcomes).
What we learn from all this. I know, I know, is a bit boring, but the idea is that union it is strength, and it is important to be constantly challenged by your friends and colleagues achievements. This is how you can become better. Imagine learning to run for a marathon. You think you will compete better if you train with:
A. people aged more than 60 years
B. professional athletes
C. children under 8 years
You get it, right? But here come another tricky reasoning. What do you know about illusory superiority? Not much. OK, let me tell you more. Illusory superiority is a cognitive bias whereby individuals overestimate their own qualities and abilities, relative to others. This is evident in a variety of areas including intelligence, performance on tasks or tests, and the possession of desirable characteristics or personality traits. It is one of many positive illusions relating to the self, and is a phenomenon studied in social psychology. Illusory superiority is often referred to as the above average effect. Other terms include superiority bias, leniency error, sense of relative superiority, the primus inter pares effect, and the Lake Wobegon effect (named after Garrison Keillor's fictional town where "all the children are above average"). The phrase "illusory superiority" was first used by Van Yperen and Buunk in 1991. Or the other extreme, that is underlined in articles like this one.
JR Harris suggested in The Nurture Assumption that an individual's peer group influences their intelligence greatly over time, and that different peer group characteristics may be responsible for the black-white IQ gap. Several longitudinal studies support the conjecture that peer groups significantly affect scholastic achievement, but relatively few studies have examined the effect on tests of cognitive ability. There is some evidence that peer groups influence tests of cognitive ability, however. The peer group an individual identifies with can also influence intelligence through the stereotypes associated with that group. The stereotype threat, first introduced by Claude Steele, is the idea that people belonging to a stereotyped group may perform poorly in a situation where the stereotype is relevant. This has been shown to be a factor in differences in intelligence test scores between different ethnic groups, men and women, people of low and high social status and young and old participants. For example females who were told that women are worse at chess than men, performed worse in a game of chess than females who were not told this.
Anyway, in conclusion, my grandfather was probably right, with his advice "try to not be the most intelligent person in the room, wherever you will be", if i see it this way. Are many other researches, most of them supporting the theory, some of them finding arguments against, but the common sense dictate that constant stimulation, coming from your peer group, will have indeed a role in developing better memory and above average intelligence skills.
Merry Christmas everyone!