You are here: MEDICA Portal. MEDICA Magazine. Topic of the Month. Volume archives. Our Topics in 2011. Topic of the Month June: Gender Medicine.
- Man under the influence of hormones
To which extent are character
and personality acquired or
natural phenomena in men and
However, these depictions and assessments of common human behaviors originate in situational and largely superficial observations. When a hormonal situation serves as an explanation, science is typically far-off.
What’s true is that hormones are involved in the body’s metabolic processes and also regulate basic human needs like sleep, hunger and sexuality. Yet what type of role does the hormonal situation have on behavior? What kind of gender-specific hormonal differences are there between men and women– are hormones even, as is often claimed, the trigger of the “small differences“? Is it possible by now to medically or biologically justify clichés like “men behave more aggressively“ and “women are more compassionate“ or to refute them?
The science of gender medicine is still in its infancy. Many questions pertaining to different scientific disciplines remain unanswered. Early findings on the fact that men and women don’t tick the same way after all, as was initially assumed, were discovered by cardiology. However, how basic hormonal functions in the body impact gender-specific behavior and how they are mutually dependent is being further investigated.
The chemical messengers and their tasks
The original Greek meaning of the word “hormon“, already hints at its task in the human body. It means to “set in motion”. To date, scientists were able to analyze over 100 hormones in the human organism, which act in a delicately complex communication system and for instance regulate remote organs or glands or serve as an information provider for neural transmission.
Scientists suspect a significantly larger number of these chemical messengers – there is talk about far more than 1000. Here is one example for this: Estrogen is a generic term for the most important female sex hormones, like for instance Estradiol, Estron and Estriol. There are over 30 different hormones that are combined in this group alone.
And so it’s not surprising that it will still take some time until this complex and multilayer system of hormonal information transfer will be understood. This also applies to research on human behavior and the power of hormones: So far studies were primarily reserved for animal research. Only now studies on humans are coming to the forefront.
Typically male – typically female: The environment, genes or hormones?
Nurture or nature – scientific disciplines have argued for some time, to which extent character and personality are acquired or natural phenomena. The truth is probably somewhere in the middle. One very well researched question by now is how the different hormonal situations, the influence of sex hormones prior to birth already impact the fetus in the womb. A multitude of scientific findings show that the brain of both genders in the first early stages of life already develops in different directions through hormones. The differences between men and women are apparently already being determined in the womb and very early on lay the foundation for different behavioral patterns later in life.
The brain continues to assume the job of being the control center of the human hormonal system. From here, the hormonal messages in turn regulate the activities of the subordinate ductless glands. Only then does the gland hormone production have a direct impact on a specific target organ.
The brain is particularly closely interlocked with the nervous system, since the stimuli that are being transmitted through the environment to the nerves also cause the hormonal control of the body functions. In this way, the nervous system and the endocrine system interlock and coordinate with each other.
Now these facts may make it seem that a large part of a human being is hormonally controlled. Doctor Schmid of the University Medical Center Schleswig-Holstein and Congress secretary of the 117th Congress of the German Society for Internal Medicine clarifies: “Human behavior is of course not exclusively controlled by hormones. In fact, the hormonal foundation provides a basis, but there is a whole number of other influences that shape human behavior. The hormonal situation is a modulator in this. “
How some hormones flow through the body at what time is decided in the hypothalamus, which translates nerve signals into chemical signals;©panthermedia.net/Sebastian Kaulitzki
The influence of sex hormones
The biological standard configuration of men and women depends on hormones as well as also on genes. At the moment different studies are researching on how exactly the gender-specific behavior is influenced by this. What has been known for some time now: “Testosterone is the classic male sex hormone and naturally exists in a definitely higher concentration in the blood of men than women. For example, female sex hormones are estrogen, oxytocin or proctalin, “ Schmid explains. “In women the hormone concentration in the body is subject to fluctuations throughout the menstrual cycle, during which the sex hormones may vary either to the high or low side.” And so hormonal messages vary in their strength.
How some hormones flow through the body at what time is decided in the hypothalamus, which translates nerve signals into chemical signals. However, the body comes with different hormone factories. The hypothalamus is responsible for the sex hormones: the creation of the follicle-stimulating hormone (FSH) and the luteinizing hormone (LH), which in a woman stimulate the maturation of human eggs in the ovaries and trigger ovulation and in men cause sperm production. Sometimes the distinction between male and female sex hormones is misleading, since the typical female hormones can also be found in the body of men in lesser concentration. Schmid explains how the gender-specific hormones act: “These messengers are of pivotal importance to the behavioral level. In this instance, testosterone is often categorized as the male hormone and is associated with aggressive behavior. In women, oxytocin among other things is associated with empathy and crucial for an intensive mother-child bond.“
Sex hormones like estrogen and testosterone slowly develop in specific phases of life and shape the gender-specific physical characteristics. The fact that some dispositions can depend on the concentration and strength of chemical substances is something the human organism underwent at the latest since puberty. Human moods are also influenced by other messengers like dopamine, procatin and oxytocin. Now scientists have more specifically analyzed the efficiency factor of the latter hormone.
The “softener“ among the sex hormones
A new study by the University of Bonn, Germany, in cooperation with the Babraham Institute in Cambridge UK, is dedicated to the research of the neuropeptide oxytocin. In the body it assumes multi-purpose functions, to create emotions and at first was known as the hormone that induces labor in pregnant women. The spectrum reaches much further: due to affection, love and trust and the so-called “bonding“ between mother and child, the hormone has the reputation of being the cuddle hormone or messenger of love. Oxytocin is also a neurotransmitter that causes substantial modulation of the prevailing mood in the brain.
Now researchers managed to modulate the emotional empathy through oxytocin and in doing so to find a key for understanding human behavior. “Men for instance were administered oxytocin as a nasal spray, because the peptide hormone arrives directly in the brain via the lamina cribrosa, the small cartilaginous section at the ceiling of the mucous membrane. Based on neurocognitive testing, the scientists then were able to determine that male test persons, who received a placebo inhalation, showed significantly lower empathy values than those who took the oxytocin,“ says Schmid.
The fact that the oxytocin group reacted clearly more empathetic to emotional pictures was also proven in a questionnaire. Both oxytocin and the control group had to solve different memory tasks on the computer. For a correct answer, a praising face was shown, for a wrong answer a dispraising face appeared on the screen. As an alternative, the answers were also revealed with green or red circles. It revealed that the learning success was clearly greater when the faces appeared on the screen – this was particularly true for the oxytocin group.
New gained insights: Behavior and hormones
In the future it will be crucial to implement these new insights from gender medicine, the gender-based medicine and to internalize them – to disengage from stereotypes and to check into gender-specific distortions that determined practices for decades. Besides gender-specific differences, personalized medicine has also stepped into the spotlight. Maybe in the future besides differences between the sexes, individual factors of the individual organism will be more strongly considered.
The findings from the oxytocin study on the interaction between brain, hormones and behavior have a considerable significance. The study made it clear, that there is a connection between sex hormones and cognitive and emotional skills. And lastly there remains one question: Cuibono? As a benefit to whom? “It certainly is not the primary goal of this research to create a nasal spray that makes men more emotional. The focus is rather on the scientific questions about the basics, which certainly could be important for the development of specific treatment concepts,“ Schmid sums up. In the future, the hormone could for instance be used as a Schizophrenia drug, since this disease is often combined with a lack of interpersonal and social skills.
(Translated by Elena O'Meara)