Case study and replication
Case study
Definition: An in-depth study of one person. Much of Freud's work and theories were developed through individual case studies. In a case study, nearly every aspect of the subject’s life and history is analyzed to seek patterns and causes for behavior. The hope is that learning gained from studying one case can be generalized to many others. Unfortunately, case studies tend to be highly subjective and it is difficult to generalize results to a larger population.
Replication
Definition: A term referring to the repetition of a research study, generally with different situations and different subjects, to determine if the basic findings of the original study can be generalized to other participants and circumstances.
Useful terms taken from about.com psychology
Question: What Is Reliability?
Answer: Reliability refers to the consistency of a measure. A test is considered reliable if we get the same result repeatedly. For example, if a test is designed to measure a trait (such as introversion), then each time the test is administered to a subject, the results should be approximately the same. Unfortunately, it is impossible to calculate reliability exactly, but there several different ways to estimate reliability.
Question: What is Validity?
Answer: Validity is the extent to which a test measures what it claims to measure. It is vital for a test to be valid in order for the results to be accurately applied and interpreted.
Validity isn’t determined by a single statistic, but by a body of research that demonstrates the relationship between the test and the behavior it is intended to measure. There are three types of validity:
Content validity:
When a test has content validity, the items on the test represent the entire range of possible items the test should cover. Individual test questions may be drawn from a large pool of items that cover a broad range of topics.
In some instances where a test measures a trait that is difficult to define, an expert judge may rate each item’s relevance. Because each judge is basing their rating on opinion, two independent judges rate the test separately. Items that are rated as strongly relevant by both judges will be included in the final test.
Criterion-related Validity:
A test is said to have criterion-related validity when the test is demonstrated to be effective in predicting criterion or indicators of a construct. There are two different types of criterion validity:
•Concurrent Validity occurs when the criterion measures are obtained at the same time as the test scores. This indicates the extent to which the test scores accurately estimate an individual’s current state with regards to the criterion. For example, on a test that measures levels of depression, the test would be said to have concurrent validity if it measured the current levels of depression experienced by the test taker.
•Predictive Validity occurs when the criterion measures are obtained at a time after the test. Examples of test with predictive validity are career or aptitude tests, which are helpful in determining who is likely to succeed or fail in certain subjects or occupations.
Construct Validity:
A test has construct validity if it demonstrates an association between the test scores and the prediction of a theoretical trait. Intelligence tests are one example of measurement instruments that should have construct validity.
More About Psychology Research
United States Map
http://atlas.nrcan.gc.ca/site/english/maps/reference/international/usa/map.jpg
This link takes you to a map where you can check where some of the locations of the studies we learnt about took place.
Child development theories Important for project
http://www.child-development-guide.com/child-development-milestone.html
Stages of Development by Jean Piaget Theories in project
http://ehlt.flinders.edu.au/education/DLiT/2000/Piaget/stages.htm
Useful link to developmental milestones
http://www.earlychildhoodeducation.co.uk/developmental-stages-preschoolers.html
Child study instructions
INSTRUCTIONS ABOUT CHILD STUDY AND INVESTIGATION NEEDS TO BE VIEWED ON PREVIOUS ENTRY. MAY 11 th ,2008
Aggression, for third polimodal only
Aggression, learning by imitation. Food for thought, some studies in psychology are still worth thinking and reflecting about.
useful vocabulary for Psychology
Snap shot study
A snap shot study is a study carried out over a very short period of time such as hours and days. In comparison a longitudinal study is carried out over a longer period of time such as weeks, months or years.
Snap shot studies are obviously quicker and cheaper to carry out than longitudinal approaches and rarely suffer from attrition. However they only provide us with a ‘snapshot’ of human behaviour and experience and therefore are not so useful when investigating development.
Experiment
An experiment is a research method used by psychologists which involves the manipulation of variables in order to discover cause and effect. It differs from non-experimental methods in that it involves the deliberate manipulation of one variable, while trying to keep all other variables constant.
The two main types of 'true' experiments are laboratory experiments and field experiments.
When psychologists carry out experiments they use one of three basic experimental designs to investigate the effects of an independent variable on a dependent variable. These are the independent measures design, the repeated measures design and the matched pairs design.
Independent Measures Design
If two groups in an experiment consist of different individuals then this is an independent measures design.
The main advantage of an independent measures design is that there is no problem with order effects.
However, the design also has disadvantages. The most serious is the potential for error resulting from individual differences between the groups of participants taking part in the different conditions.
Also if participants are in short supply, then an independent groups design may represent an uneconomic use of those available to participate, since twice as many participants are needed to obtain the same amount of data as would be required in a two-condition repeated measures design.
Roger Sperry´s study on lateralisation
Dr. Sperry used a tachistoscope to present visual information to one hemisphere or the other. The tachistoscope requires people to focus on a point in the center of their visual field. Because each half of the visual field projects to the opposite site of the brain (crossing in the optic chiasm), it is possible to project a picture to either the right hemisphere OR the left hemisphere.
Instructions for observations for 2nd pol Child
To hand in your observation
Choose the area and plan the activities.
You should choose activities which will show over a period of four months the changes and development of your child. They can also be compared over what you watched last year.
Check in the blog the entry on developmental milestones. Check the age of the child get ideas and carry them out. Suppose you are on the 2 year old and you are observing social skills , you can have a look at the type of play or his being less egocentric.
suppose you are observing a four year olds intellectual development, in this page it talks about language skills. add to this everything we have done about intellectual development.
hand in observation with good planning, otherwise it will be incomplete.
Any doubts ask or e mail for further instructions.
children´s books
Haney, banks and zimbardo St mark´s 3rd pol
Zimbardocomprehension exercise
1. How many participants were used?
2. How did Zimbardo obtain them?
3. How were the participants assigned to the role of prisoner or guard?
4. What were the guards told they must do?
5. Describe two parts of the guards’ uniform?
6. What initially took ten minutes and towards the end of the study lasted several hours?
7. How long did the study last?
8. How long was it planned to last
9. Give one criticism of the study
10. What was the aim of the study?
11. Describe two parts of the prisoners’ uniform.
12. Who played the part of the prison Warden
Hope brain tutorial
Questions to answer as you browse through the tutorial
What functions would you attribute to the brain?
What does the CNS do?
which are the functions of the glial cells?
How is the brain protected?
What is the cerebrospinal fluid?
What is the cerebral cortex?
Which are the functions of the two hemispheres?
What is the corpus callosum? Remember you will hear about this part in the study by Sperry.
Name the lobes and each of the functions.
Why is the limbic system associated with psychology and behaviour?
Which are the functions of the cerebellum?
What is the brain stem?
Build the brain as suggeste in the tutorial and draw it in your folder.
Pregnancy time line
Dear first polimodal girls
Welcome to Child Development.
Follow the time line and find out what happens in the womb.
Challenge your senses Second polimodal Humanities
Do yoy always believe what you see'?
In this BBC test and the optical illusions you can make up your mind.
To discuss in class.
family types Practical work 1st polimodal students
Look at these photographs and identify the types of families. What advantages and disadvantages can you find of each?
Practical assignment psychology 2nd pol Humanities
What laws of perception are being followed in each of these imagines. Name and explain. Find one other example of each of these laws.
Autism Definition and signs
Autism is a complex developmental disability that typically appears during the first three years of life and affects a person’s ability to communicate and interact with others. Autism is defined by a certain set of behaviors and is a "spectrum disorder" that affects individuals differently and to varying degrees. There is no known single cause for autism, but increased awareness and funding can help families today.
In February 2007, the Centers for Disease Control and Prevention issued their ADDM autism prevalence report. The report, which looked at a sample of 8 year olds in 2000 and 2002, concluded that the prevalence of autism had risen to 1 in every 150 American children, and almost 1 in 94 boys. The issuance of this report caused a media uproar, but the news was not a surprise to ASA or to the 1.5 million Americans living with the effects of autism spectrum disorder. Nonetheless, the spotlight shown on autism as a result of the prevalence increase opens opportunities for the nation to consider how to serve these families facing a lifetime of supports for their children.
Currently, ASA estimates that the lifetime cost of caring for a child with autism ranges from $3.5 million to $5 million, and that the United States is facing almost $90 billion annually in costs for autism (this figure includes research, insurance costs and non-covered expenses, Medicaid waivers for autism, educational spending, housing, transportation, employment, in addition to related therapeutic services and caregiver costs).
Know the Signs: Early Identification Can Change Lives
Autism is treatable. Children do not "outgrow" autism, but studies show that early diagnosis and intervention lead to significantly improved outcomes.
Here are some signs to look for in the children in your life:
Lack of or delay in spoken language
Repetitive use of language and/or motor mannerisms (e.g., hand-flapping, twirling objects)
Little or no eye contact
Lack of interest in peer relationships
Lack of spontaneous or make-believe play
Persistent fixation on parts of objects
Last updated: 21 January 2008
William C. Dement Study on Sleep
William C. Dement, MD, PhD is the world's leading authority on sleep, sleep deprivation, and the diagnosis and treatment of sleep disorders.
Biography
In 1970, he founded the world's first sleep disorders center at Stanford University. In 1975, he launched the American Sleep Disorders Association (now American Academy of Sleep Medicine) acting as President during its first twelve years. Dr. Dement is the founder of the American Board of Sleep Medicine which examines and certifies physicians who wish to specialize in sleep medicine. He is co-editor of the definitive sleep medicine textbook, “Principles and Practice of Sleep Medicine,” and founding co-editor of the premier scientific journal, “Sleep.” Since 1971, Dr. Dement has taught the popular “Sleep and Dreams” course at Stanford University and has written the first undergraduate textbook on this topic. Dr. Dement also served as chairman of the congressionally mandated National Commission on Sleep Disorders Research whose study and recommendations led directly to the creation of a new agency within the National Institutes of Health, the National Center on Sleep Disorders Research.
In addition, to his scientific and academic achievements, Dr. Dement serves as Chief Scientific Advisor to SleepQuest and continues to research the effect early detection and comprehensive treatment of Sleep Apnea can have on lowering overall healthcare utilization and costs.
He lives with his family on the campus of Stanford University and is dedicated to supporting family physicians who annually screen patients about their sleep health.
Dr. Dement's Top Initiatives:
Create measurable progress toward public awareness concerning sleep. Create age appropriate curriculum and ensure mandatory inclusion in grade school, high school and college curriculums.
Require mandatory, in-depth training for the most common sleep disorders and their relationship to other co-morbidities and symptoms. Create measurable progress concerning how primary care physicians conduct medical appointments for their knowledge as well as behavior toward sleep disorders; to cause higher identification of afflicted patients.
Identify all very severe obstructive sleep apnea patients and assure that they are treated successfully.
Improve timely access for the diagnosis of sleep disorders by allowing the 80% of people who do not live near a sleep specialist, to be able to choose ambulatory sleep testing as a viable diagnostic tool.
Make the public aware that "drowsiness is red alert!" — so that each person becomes knowledgeable of their own fatigue limits.
Emotional states
What do you think of these pictures?
When we get to Schaster and Singer we will learn something about all this. Does the brain have anything to do with this?
Split brain experiments
The Split Brain Experiments
Background
Nobel Laureate Roger Sperry.
In the 19th century, research on people with certain brain injuries, made it possible to suspect that the "language center" in the brain was commonly situated in the left hemisphere. One had observed that people with lesions in two specific areas on the left hemisphere lost their ability to talk, for example.
The final evidence for this, however, came from the famous studies carried out in the 1960s by Roger Sperry and his colleagues. The results of these studies later led to Roger Sperry being awarded the Nobel Prize in Physiology or Medicine in 1981. Sperry received the prize for his discoveries concerning the functional specialization of the cerebral hemispheres. With the help of so called "split brain" patients, he carried out experiments (just like the one you can perform by yourself in the Split Brain Experiments Game), and for the first time in history, knowledge about the left and right hemispheres was revealed.
What Does "Split Brain" Mean?
In the 1960s, there was no other cure for people who suffered from a special kind of epilepsy than by cutting off the connection, corpus callosum, between the two hemispheres. Epilepsy is a kind of storm in the brain, which is caused by the excessive signaling of nerve cells, and in these patients, the brain storm was prevented from spreading to the other hemisphere when the corpus callosum was cut off. This made it possible for the patients to live a normal life after the operation, and it was only when carrying out these experiments one could notice their somewhat "odd behavior."
Each hemisphere is still able to learn after the split brain operation but one hemisphere has no idea about what the other hemisphere has experienced or learned. Today, new methods and technology in split brain operation make it possibleto cut off only a tiny portion and not the whole of the corpus callosum of patients.
What Came Out of the Split Brain Experiments?
Right vision field is connected to the left hemisphere. Left vision field is connected to the right hemisphere.
The studies demonstrated that the left and right hemispheres are specialized in different tasks. The left side of the brain is normally specialized in taking care of the analytical and verbal tasks. The left side speaks much better than the right side, while the right half takes care of the space perception tasks and music, for example. The right hemisphere is involved when you are making a map or giving directions on how to get to your home from the bus station. The right hemisphere can only produce rudimentary words and phrases, but contributes emotional context to language. Without the help from the right hemisphere, you would be able to read the word "pig" for instance, but you wouldn't be able to imagine what it is.
"The great pleasure and feeling in my right brain is more than my left brain can find the words to tell you."
Roger Sperry
Sleep and sleep cycles
Although we view sleep as an escape from the activity of the day, sleep is a fairly active process itself. Throughout a healthy night's sleep, structures in the hypothalamus and brain stem cycle repeatedly through five stages characterized by different brain waves produced during the cycles. The five cycles can be broken up into two main categories: REM (rapid eye movement) and non-REM (slow wave) sleep cycles (Waxman, 2003). This web page will focus on REM and non-REM sleep, but for more information on the specifics of the four sleep cycles, visit http://www.medicinenet.com/sleep/article.htm.
REM sleep, the most crucial part of the sleep cycle (studies have shown that rats deprived of REM sleep have prolonged learning and memory difficulties (Kim et al., 2005), occurs 70 to 90 minutes after falling asleep. REM sleep is initiated by dorsal midbrain and pontine tegmentum neurons. During the REM cycle, sometimes referred to paradoxical sleep, the locus ceruleus releases norepinephrene, a neurotransmitter in the brain that affects food intake, levels of arousal, and mood (Kalat, 2004). The brain then produces delta waves, waves nearly identical to ones observed when a person is awake (Figure 2). Along with a shift in brain waves, often heart rate and blood pressure increase, intense visual imageries (dreams) occur, and muscles can often become temporarily paralyzed. Narcoleptics still experience REM sleep, but instead of entering sleep at stage one and progressing to REM sleep, they often instantly enter REM sleep upon falling asleep. This sudden loss of consciousness and muscle control endangers narcoleptics and sometimes those around them (MedicineNet, 2005).
Figure 2. Brain waves collected by an electroencephalograph (EEG). Notice the similarity between the awake, alert waves and REM sleep waves. Permission pending, http://sun.science.wayne.edu/~bio340/StudentPages/Soliman/physweb.html
As stated previously, the hypothalamus is a structure in the brain that regulates the onset of sleep stages. Within the hypothalamus, hypocretins reside in cells and possibly aid in regulating the neurons involved in REM sleep. Some researchers believe that when Hcrtr2 is stimulated in humans with normal sleep patterns, hypocretins promote wakefulness and repress REM sleep. However, in narcoleptics, a mutation in Hcrtr2 disables this pathway, allowing the sudden onset of REM sleep (http://www.healthgene.com/canine/C110.asp).
Scans
Magnetic Resonance Imaging (MRI) is a special type of procedure that allows a doctor to see what is happening inside your child's body. Unlike X-rays, the MRI scanner uses a magnetic field and radio waves to produce very clear and detailed pictures of parts of the body, such as the head, heart, chest, abdomen, pelvis, spine and extremities. MRI gathers soft tissue images and is used to evaluate function and structure of organs and to distinguish normal, healthy tissue from tissues that may need to be studied for disease.
Position Emission Tomography (PET) measures emissions from radioactively-labeled chemicals that have been injected into the bloodstream, and uses the data to produce images of the distribution of the chemicals in the body.
In drug abuse research, PET is being used for a variety of reasons including: to identify the brain sites where drugs and naturally occurring neurotransmitters act; to show how quickly drugs reach and activate receptors; to determine how long drugs occupy these receptors; and to find out how long they take to leave the brain. PET is also being used to show brain changes following chronic drug abuse, during withdrawal from drug use, and during the experience of drug craving. In addition, PET can be used to assess the effects of pharmacological and behavioral therapies for drug addiction on the brain.
What is MEG?
Marker coils placed on volunteer's head
Magnetoencephalography (MEG) is a non-invasive neurophysiological technique that measures the magnetic fields generated by neuronal activity of the brain. The spatial distributions of the magnetic fields are analyzed to localize the sources of the activity within the brain, and the locations of the sources are superimposed on anatomical images, such as those obtained through MRI, to provide information about both the structure and function of the brain.
'Clear smoking link' to cot death
The Bristol University team said the risk also increased with every hour babies were exposed to passive smoke after birth.
The number of cot deaths has fallen, but those linked to smoking have risen.
The report, to be published in the journal Early Human Development, suggests public smoking bans will make people more likely to smoke at home.
Many other studies have shown a clear link between smoking and cot death, but the Bristol research tries to unravel more precisely the cost of smoking both before and after birth.
Smoking among pregnant women has fallen from 30% to 20% in the last 15 years.
Back sleeping
The experts found that the proportion of babies who went on to die from Sudden Infant Death Syndrome (SIDS) who were born to mothers who smoked during pregnancy had risen from 57% to 86%.
This, they say, is mostly due to the success of campaigns to lay babies on their backs to sleep, which is credited with preventing hundreds of cot deaths.
The remaining cot deaths are now much more likely to be due to smoking.
The report, from the university's Institute of Child Life and Health, said that fresh messages about the dangers of smoking while pregnant had to be given to women.
Lead author Professor Peter Fleming said: "What we have been trying to do is look at the whole impact of exposure, both before and after birth, to smoking and its adverse effects.
"After delivery, the mother can reduce the risk by protecting her baby and not smoking near it."
Hour by hour
He found that for every hour a newborn was exposed to tobacco smoke, the risk increased.
"We found a perfectly linear relationship," said Professor Fleming.
"The risk of death increased with each individual hour the baby was exposed to smoke.
"For example a baby exposed to smoke eight hours a day was eight times more likely to die from SIDS than a baby that was never exposed. These are startling statistics."
He said that although the recent introduction of smoking bans in public buildings led to a "potential increase" in smoking at home, the findings might send an "encouraging" message.
"What it is saying to parents as a positive message is 'even if you can't give up smoking, don't smoke around the baby'."
Professor George Haycock, from the Foundation for the Study of Infant Deaths said: "The figures show that maternal smoking is now the most important avoidable risk factor for Sudden Infant Death Syndrome (SIDS).
"If no women smoked in pregnancy, about 60% of cot deaths could be avoided. This means that in the UK the number of deaths could fall from around 300 a year to 120 a year."
Story from BBC NEWS:
http://news.bbc.co.uk/go/pr/fr/-/2/hi/health/7045230.stm
Published: 2007/10/15 12:18:11 GMT
Epilepsy
Epilepsy
Epilepsy is caused by surges of electrical activity
Epilepsy is a common neurological disorder which causes seizures.
One in 133 people in the UK has epilepsy, and at any one time 300,000 have an active form of the condition.
What causes epilepsy?
An epileptic seizure is caused by over-activity of the brain cells, which produces a surge of electricity.
This may be due to a variety of factors, such as brain damage from birth injuries, head injury, stroke, brain tumours and alcoholism.
There is some evidence to suggest the condition sometimes has a genetic basis - although it is rare for it to run in families.
In many instances, the cause of the condition is a mystery.
Are there different types of seizure?
Yes. Essentially, there are two types.
A partial seizure begins in one specific part of the brain, and may spread to other areas.
A generalised seizure can start in both sides of the brain at once.
Partial seizures:
Simple partial seizure - Confined to one particular area of the brain. The person retains consciousness, but may be fearful, and experience a strong sense of deja vu. Symptoms include jerking of an arm and an unpleasant taste in the mouth.
Complex partial seizure - The electrical disturbance spreads, disrupting consciousness. The person may interact with the surroundings, but be unaware of what they are doing and have no recollection of the event.
Symptoms may include repeatedly chewing, swallowing or scratching. Afterwards the person is likely to be confused for some minutes.
Generalised seizures:
Tonic clonic seizure - This leads to 'grand mal' convulsions in which the person loses consciousness, falls to the ground, becomes stiff and shakes.
In some instances a tonic clonic seizure may occur after an initial partial seizure - in which case the person may have some warning of what is about to occur.
Absence attack - A blank spell lasting a matter of seconds from which recovery is almost immediate.
Myoclonic seizures - Jerks caused by a sudden contraction of the muscles. Can affect the whole body usually restricted to one or both arms and sometimes the head.
Tonic seizures - All the muscles contract. The body stiffens and the person will fall over if unsupported.
Atonic seizures - All muscle tone is lost and the person simply drops to the ground.
How is epilepsy treated?
There are a wide range of anti-epileptic drugs to prevent seizures.
Which drug is prescribed will depend on the individual patient, and their particular form of epilepsy.
The drugs are effective, but can have side effects, including drowsiness and dizziness.
Some drugs may produce longer term side effects, such as acne and weight gain.
Anti-epileptic drugs should not be taken in tandem with some other medications. They may also slightly increase the risk of malformations if taken during pregnancy.
Is surgery an option?
Yes, for people who do not respond to drug treatment.
The most common form of surgical treatment is to remove the hippocampus - a part of the brain involved in memory which is particularly vulnerable to damage.
Other forms of surgery which may be considered include:
Temporal lobectomy - a larger part of the temporal lobe is removed.
Sub-pial resection - fine cuts are made in the motor areas of the brain.
Hemispherectomy - the removal of the whole of one side of the brain
Corpus callosotomy - cutting the fibres that connect the two halves of the brain.
An alternative to neurosurgery is a treatment called vagal nerve stimulation in which a pacemaker device is placed under the skin to stimulate the vagus nerve in the neck.
This form of treatment does not usually cure the epilepsy, but can reduce seizure frequency and severity.
Drink and prematurity
'Drink link' to premature birth
Doctors say women who drink heavily early in a pregnancy - possibly before they know they are pregnant - may be raising the risk of premature delivery.
A study of 4,719 Australian women found almost an 80% higher risk for women who drank heavily in the first third of pregnancy, then stopped.
However, experts warned it was possible the results were a "statistical quirk".
The BJOG journal study found no evidence of problems for women who drank low levels throughout pregnancy.
The subject of alcohol and pregnancy has been controversial, with some guidelines advocating no alcohol intake, while other specialists believe that drinking small amounts is unlikely to harm the developing child.
The latest study suggests that the period during which binge or heavy drinking can have the greatest effect is during the first trimester.
With as many as 40% of pregnancies unplanned, this may include several weeks in which the woman is unaware she is carrying a child.
Unusually, the strongest link between alcohol use and early birth was for women who drank moderately or heavily - several units of alcohol or more a week - during the first trimester, but then stopped completely for the rest of the pregnancy.
The researchers suggested that it was possible that the sudden cessation of alcohol drinking might provoke inflammation which could harm the developing foetus in some way, although this idea was not tested during the study.
Caution urged
Dr Colleen O'Leary, from the University of Western Australia, who led the study, said: "The risk of pre-term birth is highest for women who drink heavily or at binge levels.
"Women should be advised that during pregnancy, drinking alcohol above low levels increases the risk to the baby and that the safest choice is not to drink alcohol during pregnancy."
The editor of the British Journal of Obstetrics and Gynaecology, Professor Phillip Steer, said the study represented a warning to women.
He said: "When you consider the number of pregnancies which are not planned, it is quite possible that by the time a woman realises she is pregnant, it is too late and the damage has been done."
However, Professor Andrew Shennan, representing baby charity Tommy's, said that the results needed to be interpreted cautiously.
"It is still possible that, given the relatively small number of women involved, this finding could be a statistical quirk.
"More research needs to be done to ascertain the true extent of the risk posed by drinking alcohol during pregnancy.
"This is a controversial area with many conflicting results and recommendations about what is deemed a 'safe' level of alcohol consumption."
However, he said that a precautionary approach was still sensible for women who might fall pregnant.
"Now that you can buy kits which can tell you whether you are pregnant before you have even missed a period, perhaps women who binge drink should take advantage of these."
Story from BBC NEWS:
http://news.bbc.co.uk/go/pr/fr/-/2/hi/health/7839671.stm
Published: 2009/01/21 00:11:43 GMT
© BBC MMIX
Autism some facts
Autistic traits 'spread widely'
Autism is more often diagnosed in boys
Many children have mild autistic "symptoms" without ever having enough problems to attract specialist attention, say UK researchers.
The Institute of Child Health team says diagnosed children have severe versions of character traits probably shared by millions of others.
The 8,000 child study found even these mild traits could impair development.
Boys - who make up the bulk of autism diagnoses - were most likely to be affected, the US journal study found.
Clinicians and those involved in education need to aware that there are children who do not have autism but who nevertheless have somewhat elevated levels of autistic traits
Professor David Skuse
Institute for Child Health
Scientists have understood for some time that the "autistic spectrum" covers a wide range of children with differing levels of problems, from relatively mild cases to severely disabling problems.
However, a relatively small number of children - approximately 116 per 10,000 - are said to have an autistic disorder.
The UK research, published in the Journal of the American Academy of Child and Adolescent Psychiatry provides further evidence that the same traits do not begin and end there, but continue at into the whole population of children, just at a level which does not lead parents to seek medical help.
Seeing autism as a "distinct illness" was probably wrong, they said.
Even at this mild level, however, these characteristics - particularly problems communicating with peers and teachers - can be a disadvantage.
The findings confirmed that IQ was not an issue - the traits could be present regardless of levels of intelligence.
However, it cast some light on the differential in the numbers of boys and girls diagnosed with autism.
Girls with autistic traits appeared to be able to compensate for social communication problems if they had sufficient "verbal IQ" - a natural ability to use language well.
However, even boys with high "verbal IQ" seemed less able to overcome their communication problems.
Education awareness
Professor David Skuse, one of the researchers involved, said the results did not downplay the genuine impact of more severe autism.
However, he added: "What this does suggest is that drawing a dividing line between those with autism and the rest of the population involves taking an arbitrary decision."
"Clinicians and those involved in education need to aware that there are children who do not have autism but who nevertheless have somewhat elevated levels of autistic traits - our research suggests that these children are at slightly greater risk of developing behavioural and emotional problems."
In an accompanying editorial, Professor John Constantino, from Washington University, said that the idea that autism represented the "severe end" of a natural distribution of abilities could help scientists looking for the genetics underlying the condition, or for ways to treat it.
It could also help the development of children who were affected, but not to the level of an autism diagnosis.
He wrote: "The approach of teachers and family members to such children can vary dramatically on the basis of the perceived origins of the behaviour, and recognition of the contribution of subthreshold autistic impairments can result in far more appropriate and supportive responses than typically occur when antisocial motives are presumed."