General Replicator Theory 

Male-Female Behavior

Kevin Aylward B.Sc.




One of the  attractive features about Replicator Theory, is that it explains effortlessly why male and females behave differently. The more conventional terminology for these explanations is evolutionary psychology, but keeping everything under the banner of Replicator Theory, keeps the explanations much simpler. There are really only 3 axioms to refer to, rather then a stack of text books.

Fundamental Determinator - Women Carry The Baby

The fundamental reason for all behavior differences between male and females is the simple, and obvious, fact that it is the females who carry the baby.

It should be noted that, for various Politically Correct reasons, this undisputable fact is simple ignored. Much effort is expended in eliminating differences that result from this fact, that are in effect, quite futile as there are some millions of years of evolution programming within us based on this trivial fact. No one is denying that that equal opportunities should not be for all, however, as will be shown here, a crying male, will result in little success in attracting women. 

It is sometimes argued that male-female differences are the sole result of environmental (society) and hormone factors. This is, quite bluntly, totally absurd. This would make no sense evolutionary wise. It is also contradicted by many genetic studies. The "female carrying the baby" is such a fundamental physical attribute that there would be no credible way for this not to have physical repercussions on the traits of physical Replicators.

Male - Female Behavior

Male and females are example of Combined Replicators, as described in Replicator Theory. In actuality, it is more complicated than this. Replicators in animals, are not the animals themselves. Humans do not replicate, only the genes that the human are constructed from replicate. The human is in reality, nothing more than a host vehicle which the Replicators utilize in order to maximize their own numbers. This fact accounts for situations that which would otherwise be somewhat paradoxical. To simplify explanations, in most cases the distinction between replicator and vehicle and  replicator type and the type of its vehicle will be ignored.

A Male is an M-Replicator. It can increase its replication rate by combining with as many F-Replicators as it is able to. A Female is an F-Replicator, and cannot increases its replication rate by combining with as many M-Replicators as it is able to, as once it combines, further combinations will not result in another Replication for a significant time period. A female replicator can therefore, only increase its replication rate, by selecting a "quality" M-Replicator, and relying on the M-Replicators faster rate to carry her traits by piggyback

Thus the conclusion, that based on only random generation and selection of traits, and that females carry the baby, and also noting that the following are overall statistical results, not individual results.

1 Males will mate at every reasonable opportunity, as every mating is a potential new replication.

2 Females will mate only after evaluating for the mate that that will allow them to produce the maximum number offspring. 

That is, males are not very choosy, and will mate with essentially, any other mate. Females must be choosy. That is, in general:

It is the female that chooses who it will mate with, the male, essentially, has no relevant choice.

The idea that a male "pulls the birds" is a fiction in reality.


Typical explanations as to why females are highly selective are often based on the notion of limited resources. That is, a female invests for more resources to an offspring than the male. This is shown to be an invalid explanation as, although it is correct statement, this result has been derived without this assumption. The fact that females can not continually have offspring but have to wait until the offspring is born, is sufficient for the conclusion. That is, it is a time per generation limitation, not a resource limitation.

On immediate deduction of General Replicator Theory is that, as M-Replicators, can in principle, have an unlimited number of replications by mating with an many F-Replicators as it can, the theory predicts that:

M-Replicator offsprings will be more desired than F-Replicator offsprings, all things being equal.

This is indeed an observation in many cultures. This is often explained, erroneously, as a quality or resource issue, i.e. males are better able to fend for themselves, are the ones to hunt etc. The real reason is that males can simply replicate faster than females can, and so that is what is observed.

Summary so far

With the barest of simple assumptions, we have actually derived exactly how individuals do behave in practice. What may be considered common knowledge, is the double standards between male and females. That is, males are usually given a nod and a wink, i.e. jack the lads, if they are very successful in mating with females, i.e. having many partners. For females, it is generally frowned upon, i.e. whore, slut and similar terms are used. What we see here, is that this is just acknowledgement of the behavior that results in the maximum offspring for males and females, and is therefore a trivial prediction of General Replicator Theory. 


General Replicator Theory tell us that Replicators will take whatever action is necessary in order to increase their numbers. Because Replicators F-Replicators and M-Replicators have different characteristics, what action is taken, is dependent on the Replicator type.


We have seen that F-Replicators, are Replicators that cannot increase their numbers by quantity of combinations. That is, once an F-Replicator has mated, it can not mate for replication purposes for a significant time period. For example, for the human female, there is only approximately 30 offspring possible in a normal life span. Therefore, to increase F-Replicator numbers, an F-Replicator must be strongly selective with the Replicator that it combines with. This leads to the following simple observation:

An F-Replicator's selection criteria is to select a mate that has the traits that results in maximizing the F-Replicator's own replications. That is, an F-Replicator will select the best Replicator available, if that selection does not negatively impact her net replication rate. 

This is summed up by, a female, essentially, selects a mate based on traits she desires in her offspring, not traits she desires for herself. 

This may well be the case, even if such a mate may not be optimum as a protector and  provider for herself and her offspring because, the immediate consequence of this is:

a female will preferable chose a male that is successful with mating with other females.

as as it has already been shown that quantity always wins over quality, assuming unlimited resources. 

Having a male offspring that is also popular with females, will clearly increase the number of her own genes spread via  that popular male offspring . This is by far the best way that a female can increase her genes. It is only males that can mate indiscriminately in an effort to increase their own genetic numbers. The overall summary of this is the concept of status. 

It is further noted that even if there is a side effect in selecting the best Replicator, such as a change in its own traits, if that change does not negatively effect its net replication rate, it will still make that selection. It is quite conceivable, therefore, that in order to maximize replications, for a female to select a mate that will produce good quality gene stock, even though that selection may cause that female discomfort in other aspects. It is suggested by the author, that this would explain the somewhat contradictor behavior where females are unwilling to leave male abusers.


As noted, an M-Replicator is not very selective to the quality of the F-Replicator it mate with. However, if it does select, what will it select for?

Clearly, the most damaging genetic situation for a male, is to expend significant resources on a female who is not carrying his own genes. The consequence of this is that:

a male will preferable not choose a female who is popular with other males.

A male "knows" that another male will indiscriminately mate with, essentially, any female, so it is of little value to a male, as it is indeed the case for females, to evaluate whether a female can easily mate with other males. Its simply not a significant issue of concern. The major aspect, is the opposite, if a female is too popular with other males, there is a very large probability that she may be carrying another males offspring.

It should also be noted, that if a competitor male is simply with another female, this is a direct determinate to that male as that female is already taken. For a female, this is not so significant, as even if her desired male was to mate with other females, she can still mate with that male essentially, immediately that male has mated with those competing females. A male can not do this since a female can only produce one offspring in a time period. One mate, precludes all others.

Other Comments

Since the female "knows" that males prefer females that are unpopular with males, to attract a good quality mate, that is the strategy that a female should appear take. However, this doesn't not imply that a female does not wish to mate with other partners, only that she should appear that way. Clearly, the female still wishes to mate with the best gene stock that might came along, but this must be hidden to avoid discouraging current good gene stock.

Male-Female Ratios

The essentials of sex ratios are a trade off of on mate availability and, to a lesser extent between poorer quality and less quantity.

Consider population groups where there is an asymmetry in the number of males to female numbers.

What will maximize numbers?

Females Greatly Outnumber Males

Although there are more females to actually have offspring, they will be unable to select for quality as there are simply not enough quality males to go around. This results in the average quality of each offspring being lower. Is is also more advantage's to produce males, since any males produced will be essentially guaranteed to be able to find mates.

Female offspring can't get mates, so generate males.

Males Greatly Outnumber Females 

Although there are more males for females to select based on quality, the total numbers of offspring matings are reduced because only females can generate offspring. It is also more advantages to produce females as although in principle males can generate more offspring, in this situation, its quite likely that a male offspring might be unable to have any offspring at all since no females would be available that will select them.

Male offspring can't get mates, so generate females. 

Intermediate Ratios

Exactly what ratio is generated is obviously dependant on various selection details, but clearly there will be some nominal optimum for a given environment somewhere between 0%-100% and 100%-0%. In a monogamous, all things equal, society the ratio will be strongly driven to 1.

Female-Male Contrasts

It can be noted than that male and females are fundamentally opposed as to their basic selection criteria.

Females prefer males to be popular with other females.

Males prefer females to be unpopular with other males.


These papers may be freely copied only for non commercial use,

provided full credit is given to the author.

Kevin Aylward 2003 - all rights reserved