Innate Patterns

Innate Patterns

Understanding Animal Behavior

Question this:

  • Do only humans have reason?

  • If so, how do animals take care of themselves?

  • Instincts?

Certain behaviors are repeated very often, both individually and by animals of the same species. These regularities allow for a scientific understanding.

A stimulus is anything that causes a reaction or change in an organism or system. A response is the reaction or behavior that occurs as a result of a stimulus.

A reflex is an involuntary and nearly instantaneous movement in response to a stimulus. Reflexes are automatic and do not involve conscious thought. They are typically unlearned behaviors, often serving as protective mechanisms for the body.

Instincts

  • Some theorists suggested even that we might have more instincts

  • Whatever the case, Darwin’s theory of evolution changed our definition of “instinct”.

Learning Enables Adaptation

  • Natural selection and sexual selection

  • Depending on environmental demands, certain of these traits might result in a reproductive advantage.

  • Behavioral traits are also important

  • The ability to adapt to ones environment with experience enhances survival and/or passing one genes

  • Instincts are innate behaviors typical of a species, resulting from natural and sexual selection.

  • These terms remain controversial and vaguely defined

    • Evolutionary psychology.

Elicited Behaviors

  • Elicited Behaviors are not all learned

    • Example: spiders don’t learn to weave good webs; web-spinning is largely inherited

    • For simple animals, underlying action mechanisms are rudimentary yet powerful

    • Even simple systems are adaptive and functional in initial life stages

    • Most of these patterns involve changes in behavior as a function of changes in stimulation

Simple Orientation Mechanisms

  • Simple animals may have little or no nervous system, or a rudimentary one

  • Primitive senses guide orientation (e.g., avoidance) rather than complex cognition
    (So, for simple animals, their most fundamental senses are sufficient to direct their movement and behavior, such as avoiding threats (orientation). They don't rely on or possess complex thinking or elaborate cognitive processes to navigate their environment or react to stimuli.)

  • Tropisms:

    • Mostly associated with plants

    • Growth or turns in particular directions in response to particular stimulation (e.g., thermotropism, phototropism, and gravitropism, which allow plants to adapt to their environment by growing towards light, warmth, or gravity, respectively).

  • Taxes:

    • In simple and complex animals, involve locomotion towards or away from a stimulus

    • Ex: A moth flying towards a light source or bacteria moving away from a harmful chemical

  • Kineses:

    • Movements in random directions as a result of the intensity of stimulation

    • Ex: Woodlouse moving more rapidly and randomly in a dry, open area to increase its chances of finding a damp, sheltered spot where it can slow down and move less randomly.

Elicit Behaviors: Relexes

Reflex Action

  • Refined behavior in more complex animals depends on individual history and environment

  • Reflexes are influenced by multiple interacting mechanisms and can be simple or complex.

Reflex Action: History and Theories

  • Rene Descartes (1596–1650): proposed animals are mindless and soulless; all activities could be explained by reflexes; the idea of the “Reflex Arc”

  • By mid-1800s, physiology expanded the study of reflexes. Started to play with electricity.

    • Neural transmission and the idea that mental processes could be analyzed via reflexes

    • Ivan Sechenov argued that mental processes are reflexive responses to stimuli and could be understood through biology

Reflex Action: Definition and Key Features

  • A reflex is a stereotyped pattern (the same muscle moves in the same way) of movement of a body part elicited by a specific stimulus.

  • Characteristics:

    • Rapid, predictable, and involuntary

    • Mostly inborn (innate)

    • Present in newborns; some reflexes disappear with age

  • The stimulus–response relationship resembles a cause-and-effect link, often independent of past history, yet highly adaptive

  • Most reflexes help avoid, escape from, or minimize the impact of noxious stimuli

Properties of Reflexes (I)

  • Threshold: the stimulus must exceed a minimum level to elicit a response; expressed as S > T where S is stimulus intensity and T is threshold

    • Latency: The time required to have a reaction towards the stimulus.

    • The short latency is often due to direct sensory–motor connections in the spinal cord

    • Varies with factors such as receptor sensitivity and the number of neurons and synapses involved

  • Momentum: the response generally outlasts the stimulus that produced it

  • Temporal summation: Two subthreshold stimuli may excite a reflex when either alone would be ineffective

  • Refractory period:

    • After a response has occurred, the threshold of the reflex may be elevated for a brief time when the probability of response is zero no matter how strong the stimulus is.

Fixed Action Patterns

  • Some innate behavior patterns are more complex

    • Classical ethology: Konrad Lorenz, Niko Tinbergen, and others

  • Fixed Action Patterns (FAPs) are behavior sequences that are released by a specific environmental signal

  • They are not learned; they are built into genes,

  • Are stereotyped (occur the same every time and in every organism)

  • Continue to completion even if the guiding stimulus is removed.

  • Ex: The examples of innate patterns include reflex actions, such as the knee-jerk response, as well as instinctual behaviors like nesting in birds.

Do humans have Fixed Action Patterns?

  • Eibl-Eibesfeldt suggested that emotions like smiling and eyebrow flashing can be considered human FAPs

  • However, even innate patterns can be modified by experience: sensitivity to releasing signs can be tuned through learning, which fine-tunes responses to the environment and enhances survival

  • This shifting understanding explains why FAPs are rarely treated as completely unmodifiable. It is more of something called Modal Action Patterns.

Conclusion

  • Not all behavior is “learned”

  • The simplest animals can behave adaptively

  • Orientation reactions, taxes, kineses, tropism, reflexes, fixed and modal action patterns are basic behavioral adaptations to the environment

  • But with more complex niches, they become more complex