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1.
Anatol Rapoport 《Bulletin of mathematical biology》1947,9(2):41-61
The behavior of two individuals, consisting of effort which results in output, is considered to be determined by a satisfaction
function which depends on remuneration (receiving part of the output) and on the effort expended. The total output of the
two individuals is not additive, that is, together they produce in general more than separately. Each individual behaves in
a way which he considers will maximize his satisfaction function. Conditions are deduced for a certain relative equilibrium
and for the stability of this equilibrium, i.e., conditions under which it will not “pay” the individual to decrease his efforts.
In the absence of such conditions “exploitation” occurs which may or may not lead to total parasitism. Some forms of the inverse
problem are considered, where the form of behavior is given and forms of the satisfaction function are deduced which lead
to it. 相似文献
2.
Anatol Rapoport 《Bulletin of mathematical biology》1947,9(1):17-28
The behavior of two individuals is considered as consisting of an increase or a decrease of productive output. Motivation
for increase is the derivative of a “satisfaction function”. This is an algebraic sum of the well-known Thurstone satisfaction
curve and another essentially negative quantity, which is a product of a “reluctance parameter” and the “effort”. Each individual
attempts to maximize his own total satisfaction. The resulting behavior is examined under a variety of conditions; namely,
1) equal sharing of produced without prescribed sharing of effort; 2) various contracts prescribing the sharing of effort;
3) situations in which one individual is more aware of the underlying motivations than the other. It is these latter situations
which under the simplest assumptions of equal sharing, without prescribed sharing of effort, lead to parasitism, i.e. total
cessation of effort on the part of one individual. This happens when one individual becomes aware of the other'sautomatic adjustment of his effort so as to bring about a total optimum output, which is a constant. Parasitism is prevented by various
forms of contracts in which either the effort necessary for the total optimum output is shared according to a prescribed ratio
or the effort of one individual is fixeda priori as a function of the effort of the other. In the latter case the respective efforts become a function of a single variable,
and each of the satisfaction functions is maximized by a particular value or values of this variable. In general, these critical
values do not coincide for the two satisfaction functions. The problem of finding forms of contract which will result in identical
critical (maximizing) values of the variable for both satisfaction functions leads to a functional equation. 相似文献
3.
N. Rashevsky 《Bulletin of mathematical biology》1950,12(4):343-351
Leadership, whether executive, political or any other type, is connected with the achievement of some goal by the social group
through an appropriate organization of that group. From this point of view different leadership ranks in a group would be
assigned to individuals according to their ability to organize the group for the purpose of reaching a specific goal. The
situation is actually complicated by the circumstance that an individual may have the necessary ability but may not like the
responsibility connected with the leadership, or vice versa. Also, he may not be interested in the goal. The suggested mathematical
approach is to consider that the satisfaction of an individual is a function of his leadership rank, of the goal, and of several
other parameters. If each individual tends to adjust his position in society so as to maximize his own satisfaction, this
condition gives us the equations which determine the leadership rank of each individual. It is found that, in general, the
rank of an individual depends not only on his ability, but on the abilities of all other individuals. The method enables us
to calculate the distribution function of abilities among individuals of a given rank, and leads to results which allow, in
principle, experimental verification. 相似文献
4.
Anatol Rapoport 《Bulletin of mathematical biology》1947,9(3):109-122
Motivations of two individuals governed by a satisfaction function are assumed to determine their respective “efforts”, which
result in the production of “output”, i.e., objects of satisfaction. In previous papers the sharing of output was prescribed
in advance. In the present article, however, the sharing formula itself is determined to a certain extent by the satisfaction
function. The rate of remuneration per unit of output for each individual is taken to be proportional to the derivative of
the satisfaction of the other individual with respect to the effort of the first. The formulation of this condition leads
to a partial differential equation whose solutions determine the sharing formula. Sharing determined in this way is referred
to as sharing according to the Condition of Mutual Need (C.M.N.). Satisfaction resulting from five different situations are
the computed and compared: (1) an individual producing and consuming alone; (2) two individuals sharing equally and neither
taking the “initiative” to determine the optimum output; (3) sharing determined by C.M.N. with optimum output determined as
in (2); (4) equal sharing but with one individual taking “initiative” in determining optimal output; and (5) sharing determined
by C.M.N. and optiml output by the “initiative” of one individual. further considerations concern conditions imposed on the
arbitrary function occurring in the solution of the above-mentioned partial differential equation. 相似文献
5.
N. Rashevsky 《Bulletin of mathematical biology》1958,20(2):167-174
As suggested in previous publications, freedom may be defined quantitatively as a restriction upon the choice of a number
of activities. If the choice is determined by maximizing the satisfaction function, it is suggested that freedom may be defined
in terms of the satisfaction function. If an individual is isolated and no physical restrictions limit his choice of activities,
he is free to choose any activity in an amount which maximizes his satisfaction. This isolated state may be considered therefore
as that of maximum freedom. If the individual interacts with another, he will choose different amounts of his object of satisfaction
depending on whether he behaves egoistically or altruistically. But in either case the value chosen will not maximize his
satisfaction function considered alone. A simple analytical expression is suggested as a measure of freedom in this case,
and some problems which arise from this suggestion are mentioned. 相似文献
6.
N. Rashevsky 《Bulletin of mathematical biology》1967,29(4):863-877
The theory of imitative behavior as developed hitherto by the author was based on the assumption that each individual has
a natural preference for one of the two mutually exclusive behaviors. The endogenous fluctuations in the central nervous system
then result in the individual’s exhibiting the two behaviors alternately with a relative frequency determined by the natural
preference. Imitation shifts the natural preference towards one or the other of the two mutually exclusive behaviors. In the
present approach it is suggested that the relative frequency of the two mutually exclusive behaviors exhibited alternately
is determined by maximizing the “satisfaction function” of the individual, that is by hedonistic factors rather than by purely
random fluctuations. Corresponding equations are developed. It is shown that in certain cases, even when the imitation effect
is absent, a sort of “pseudoimitation” may occur. Another situation leads, in the case of two individuals only, to a complete
“division of labor” between them, with respect to the two behaviors. Each one exhibits only one behavior. After that imitation
is introduced explicitly by assuming that imitation by one individual or another increases the satisfaction function of the
imitating individual. Results thus obtained show similarities to the results of the old theory. 相似文献
7.
8.
N. Rashevsky 《Bulletin of mathematical biology》1949,11(3):157-163
A group of individuals is considered in which each individual has tendencies to exhibit one or another of two mutually exclusive
behaviors. Neurobiophysically this may be described in terms of Landahl's reciprocally inhibited parallel reaction chains.
The spontaneous excitations ε1 and ε2 at the central connections of each chain are a measure of the “natural” tendency of the individual toward one or the other
of the two behaviors. According to equations derived by H. D. Landahl, the probability of one or the other behavior is determined
by the difference ε1 − ε2. A population of individuals is considered in which ε1 − ε2 is distributed in some continuous way, and therefore in which the probability of a given behavior is distributed continuously
between 0 and 1. The effect of other individuals exhibiting a given behavior is to increase the corresponding ε of the individual.
Thus behavior of others affects the probability for a given behavior of each individual. It is shown that the equations describing
the behavior of the population on the basis of this neurobiophysical picture reduce in the first approximation to the differential
equations which were postulated by the author in his previous work on social behavior. 相似文献
9.
N. Rashevsky 《Bulletin of mathematical biology》1969,31(4):789-795
The author's theory of the adoption of certain types of behavior patterns (Rashevsky, N., 1957, “Contributions to the Theory
Initiative Behavior”.Bull. Maths. Biophysics,19, 91–119; 1968,Looking at History through Mathematics, Cambridge, Massachusetts: M.I.T. Press) consisting of elementary behaviors for each of which there is an opposite one and
the two are mutually exclusive, is applied to describe the changes in the general type of behavior of a society. The elementary
acts of which the whole problem consists may be either overt activities or beliefs or opinions. The general behavior patternsadopted by the society are considered as the “proper” or “just” ones. Any deviation from it in either one or more of the component
elementary behaviors is considered as “unjust” and is subject to some punitive action. The total number of possible mutually
exclusive behavior patterns is very large but finite. Within this very large range of possible patterns, we find that this
notion of justice is relative, because changes from any behavior pattern to any other may occur. It is further shown that
the amount of punishment for the deviation from the accepted pattern in order to be effective as well as efficient must be
applied in different ways to different individuals even for the same transgression. 相似文献
10.
11.
N. Rashevsky 《Bulletin of mathematical biology》1949,11(2):105-113
When an individual grows up in a society, he learns certain behavior patterns which are “accepted” by that society. He may
in general have a tendency toward behavior patterns other than those which are “accepted” by the society. This tendency toward
such unaccepted behavior may be due to a process of cerebration which results in doubt as to the “correctness” of the accepted
behavior. Thus, on the one hand, the individual learns to follow the accepted rules almost automatically; on the other hand,
he may tend to consciously break those rules. Using a neural circuit, suggested by H. D. Landahl in his theory of learning,
a neurobiophysical interpretation of the above situation is outlined. Mathematical expressions are derived which describe
the social behavior of an individual as a function of his age, social status, and some neurobiophysical parameters. 相似文献
12.
N. Rashevsky 《Bulletin of mathematical biology》1947,9(1):1-8
We may consider that most of the human behavior is a set of learned responses to certain patterns which recur frequently in
the course of human life. Some “abnormal” events or experiences may result in the learning of abnormal responses, and thus
in abnormal behavior. The “abnormal” responses may begin to be learned after some of the normal response patterns have been
fairly well established. The development of both normal and abnormal behavior may thus be represented by learning curves of
the type studied by H. D. Landahl. Applying some of the results of the theory of learning curves and considering that the
normal and abnormal reactions may reciprocally inhibit each other, a quantitative theory of some psychoses may be developed.
In particular, the effects of shock may be deduced from the assumption that they cause the more recently learned abnormal
reactions to be “unlearned” more readily, than the earlier learned “normal” reactions. The effectiveness of shock treatments
as a function of the duraction of psychosis is discussed from this point of view. 相似文献
13.
N. Rashevsky 《Bulletin of mathematical biology》1952,14(3):213-227
The concept of the satisfaction function is applied to the situation in which two individuals may each produce two needed
objects of satisfaction, or may each produce only one of the objects and then make a partial exchange. It is shown that with
a logarithmic satisfaction function there is no advantage in a division of labor, unless such a division materially increases
the purely physical efficiency of production. This result appears to be connected with the particular choice of the form of
satisfaction function (logarithmic). While the problem has not been solved for other forms, it is made plausible that satisfaction
functions which have an asymptote will lead to a different result.
Next the case is studied in which division of labor occurs between two groups of individuals. It is shown that in this case
the relative sizes of the two groups are determined from considerations of maximum satisfaction. Possible applications to
problems of urbanization are suggested. 相似文献
14.
N. Rashevsky 《Bulletin of mathematical biology》1952,14(2):137-140
Let two or more individuals each possess different quantities of two objects of satisfaction. Under certain conditions they
may agree to exchange part of the objects if this leads to an increase of each one's satisfaction. The equations which govern
this process have been derived by G. E. Evans (1930) for the case of two individuals. A different proof of these equations
is given here and the equations are generalized to the case of more than two individuals. 相似文献
15.
Ernesto Trucco 《Bulletin of mathematical biology》1954,16(4):279-316
This paper is based on N. Rashevsky's theory of imitative behavior, the underlying idea being that performance of one reaction
by a given individual produces an increased stimulation (or tendency) toward the same reaction in other individuals. For simplicity,
consideration is limited to cases in which each individual may choose only between two (or two main categories of) reactions,
denoted byA andB in the following. However, upon suggestion from Dr. Rashevsky and certainly in better agreement with actual facts, the strength
of imitative interaction is assumed to vary from individual to individual. More precisely, if Ψi denotes the additional excitation caused by imitation in theith individual,PAi the probability for performance of reactionA, andPBi the probability for performance of reactionB by theith individual, we postulate that
where the constants α
ik
′
and β
ik
′
(coefficients of imitative interaction) measure the amount of imitative influence exerted by thekth individual upon theith,N being the total number of individuals in the population. The term — αi Ψi accounts for the spontaneous decay of excitation, and the quantities α
ik
′
and α
ik
′
are assumed to benon-negative. The expressions forPAi andPBi are obtained from H. D. Landahl's theory of conflicting stimuli; they depend non-linearly on the values Ψi.
It is implicit in this formulation that the theory can only be applied if the frequency of contacts between individuals is
not too small. Some further shortcomings and limitations of the model are outlined, and the discussion includes suggestions
for reinterpretation and improvement of the theory.
If all the quantities α
ik
′
and α
ik
′
have the same value, sayA, we return to the case treated by Rashevsky (and Landau, 1950); these authors, however, replace the sums in the equation
above by integrals, which automatically restricts the validity of their results to very large values ofN. Their work may therefore be characterized by the assumption of uniform interaction in large populations. Our equations,
on the other hand, are applicable even to very small groups, and therein lies one of their main advantages.
In this paper the mathematical properties of the non-linear system of equations above are studied with particular reference
to the existence and stability of steady states [dΨi/dt ≡ 0;, i = 1 , 2, . . . N].
A sufficient condition for the existence of only one stable steady state is derived. It may be formulated roughly by stating
that all the coefficients of interaction should be sufficiently small. It that is not the case, there may exist a greater
number of stationary states. In particular, two of them (called “extremal”) have the following properties: they arestable and such that the average number of individuals in the group performing one or the other reaction is the largest (or smallest)
possible as compared with the other steady states. Hence the situation is qualitatively similar to that found by Rashevsky
and Landau.Quantitatively, however, important differences may arise, depending on the nature of the matrix specifying the interaction.
A stable state may be approached through damped oscillations, but this effect is important only if the damping is sufficiently
small for the oscillations to become practically observable. Little information could be obtained on this point, due to mathematical
difficulties.
As mentioned above, the most interesting applications of this theory will be with respect to small populations or to populations
partitioned into subgroups with varying amounts of imitative interaction within as well as between groups. 相似文献
16.
Does kin-biased territorial behavior increase kin-biased foraging in juvenile salmonids? 总被引:2,自引:0,他引:2
We examined the effects of kin-biased territorial defense behavioron the distribution of foraging attempts and percent weightchanges (fitness benefits) in juvenile Atlantic salmon (Salmosalar) and rainbow trout (Oncorhynchus mykiss) in an artificialstream channel. The individual percent weight changes and frequencyof aggressive interactions and foraging attempts were quantifiedin kin (full sibling) and non-kin groups of salmon and troutWe observed kin groups of both species to obtain significantlygreater mean and less variable percent weight gains that non-kingroups. In addition, faster-growing (dominant)individuals ofboth species within kin groups exhibited significantly feweraggressive interactions than did faster-growing nonkin individuals,while we observed no difference between kin and non-kin slower-growing(subordinate) individuals. Slowergrowing kin individuals ofboth species obtained significantly more foraging opportunitiesthan slower-growing non-kin individuals while there was no differencebetween faster-growing kin and non-kin individuals. These datasuggest that reduced aggression by faster-growing individualstowards slower-growing kin enables slower-growing kin to obtainmore foraging opportunities, resulting in higher and less variablepercent weight changes. These data also suggest that as a resultof kin-biased territorial defense and foraging behavior, juvenileAtlantic salmon and rainbow trout may be able to maximize inclusivefitness potential by defending territories near related conspecifics. 相似文献
17.
N. Rashevsky 《Bulletin of mathematical biology》1950,12(3):177-185
In previous publications, social groups have been studied in which each individual has a preference for one of two possible
mutually exclusive activities. This preference is measured by a quantity ϕ. The value ϕ=0 corresponds to no preference; a
preference for one activity is measured by a positive ϕ, the preference for the other by a negative ϕ. The quantity ϕ varies
from individual to individual. It has been shown previously that, owing to effects of imitation, even when the average ϕ for
the group is zero, one of the two behaviours will be chosen by the majority of the group. Whereas in previous studies the
imitation effect was considered as independent of the distance between the imitating and imitated individuals, in the present
study the case is considered in which the effect of imitation decreases with the distance between the individuals. It is found
that under certain conditions a greater percentage near the center of the area occupied by the group, rather than near the
periphery, exhibits the chosen behavior. The possible sociological meaning of this gradient of behavior is discussed. 相似文献
18.
W. Nakahashi 《HOMO》2017,68(2):83-100
Traumatic lesions are often observed in ancient skeletal remains. Since ancient medical technology was immature, severely traumatized individuals may have frequently lost the physical ability for cultural skills that demand complex body movements. I develop a mathematical model to analyze the effect of trauma on cultural transmission and apply it to Neanderthal culture using Neanderthal fossil data. I estimate from the data that the proportion of adult individuals who suffered traumatic injuries before death was approximately 0.79–0.94, in which 0.37–0.52 were injured severely and 0.13–0.19 were injured before adulthood. Assuming that every severely traumatized individual and a quarter to a half of the other traumatized individuals lost the capacity for a cultural skill that demands complex control of the traumatized body part, I estimate that if an upper limb is associated with a cultural skill, each individual had to communicate closely with at least 1.5–2.6 individuals during adulthood to maintain the skill in Neanderthal society, and if a whole body is associated, at least 3.1–11.5 individuals were necessary. If cultural transmissions between experts and novices were inaccurate, or if low frequency skills easily disappeared from the population due to random drift, more communicable individuals were necessary. Since the community size of Neanderthals was very small, their high risk of injury may have inhibited the spread of technically difficult cultural skills in their society. It may be important to take this inhibition into consideration when we study Neanderthal culture and the replacement of Neanderthals by modern humans. 相似文献
19.
Following a suggestion made previously (Bull. Math. Biophysics,13, 61, 1951), it is assumed that every individual has both a tendency to behavearationally, by accepting everything on faith, and rationally, by subjecting everything to rational analysis. Arational behavior is characterized
by various beliefs, prejudices, etc., which are considered to be conditioned reactions, learned by the individual before he
completely develops his faculties for rational thinking. The two tendencies are assumed to be due to excitations of two different
regions of the central nervous system, and are measured by the intensities ɛ
f
and ɛ
r
of those excitations. Those intensities are further assumed to increase linearly with time, the increases of the two beginning,
in general, at different ages. The rates of increase are considered as normally distributed in the population. The relative
frequency of arational and rational behavior is determined by the difference φ=ɛ
f
=ɛ
r
according to equations 0 developed previously (Bull. Math. Biophysics,11, 255, 1949).
It is shown that with the above assumptions the majority of the population, which starts with arational behavior, will, within
two or three of generations, either change to rational behavior or continue indefinitely to behave arationally. This will
hold as long as imitative factors are present. Expressions for the numbers of individuals who behave rationally and arationally
are derived. If the intensity of conditioning toward an arational behavior decreases with increasing size of the rationally
behaving minority, or, if the rationally behaving individuals are not influenced by imitation, then a slow secular trend toward
rational behavior may be present. An expression is also derived for the fraction of individuals who behave rationally as a
function of age. This fraction increases with increase of the age at which the beginning conditioning toward any beliefs or
prejudices begins. 相似文献
20.
Anatol Rapoport 《Bulletin of mathematical biology》1952,14(2):159-169
The propagation of a single act in a large population is supposed to depend on some external circumstance and on an “imitation
component”, where encounters with individuals who are performing or have already performed the act contribute to the tendency
of an individual to perform it. The “tendency” to perform is supposed to be measured by the average frequency of stimuli,
randomly distributed in time, impinging on the individual. The deduced equation is a relation between the fraction of the
population who have performed the act and time, provided the time course of the “external circumstance” and the way in which
the imitation component contributes are known. Several special cases are studied, in particular, cases without the imitation
component, cases with imitation only, and various mixed cases. Examples are given of social situations in which such factors
may operate and general suggestions are made for the systematization of observations and/or experiments to test the assumptions
of the theory. 相似文献