T. Böhnstedt: Körperkontakt und Sexualität Fünf- bis Sechsjähriger aus der Sicht ihrer Mütter: Bezugspersonen, Interesse, Wissen, Erfahrungen, Grenzen. M.A. Thesis, Universität Bamberg, 1992.
P.T. Cohen-Kettenis, T. Sandfort: Seksueel gedrag van kinderen: een kwantitatief onderzoek onder moeders. Tijdschrift voor Seksuologie 20:3 (1996).

Via een schriftelijke enquête in het tijdschrift Ouders van Nu werden gegevens over diverse aspecten van kinderseksualiteit verzameld. Het betreft observaties van 648 moeders van het gedrag van hun oudste kind. Deze kinderen variëren in leeftijd van 0 tot 12 jaar. Seksueel gedrag blijkt als samenhangend construct goed meetbaar. Kinderen verschillen in de mate waarin zij seksueel gedrag vertonen. Daarnaast worden niet alle gedragingen in gelijke mate gerapporteerd. 'Volwassenen' aandoend seksueel gedrag is zeldzaam, maar niet geheel afwezig in deze leeftijdsgroep. Er werden significante, maar lage verbanden gevonden tussen kenmerken van de moeders en het geobserveerde gedrag van de kinderen: moeders die een meer open lichamelijke omgang met het kind hebben en moeders die meer positieve opvattingen hebben over seksualiteit rapporteren meer seksueel gedrag.

W.N. Friedrich, P.C. Grambsch, D. Broughton, J. Kuiper, R.L. Beilke: Normative sexual behavior in children. Pediatrics 88:3 (1991), pp. 456-464.

A large-scale, community-based survey was done to assess the frequency of a wide variety of sexual behaviors in normal preadolescent children and to measure the relationship of these behaviors to age, gender, and socioeconomic and family variables. A sample of 880 2- through 12-year- old children screened to exclude those with a history of sexual abuse were rated by their mothers using several questionnaire measures. The frequency of different behaviors varied widely, with more aggressive sexual behaviors and behaviors imitative of adults being rare. Older children (both boys and girls) were less sexual than younger children. Sexuality was found to be related to the level of general behavior problems, as measured by the Achenbach Internalizing and Externalizing T scores and to a measure of family nudity. It was not related to socioeconomic variables.

W.N. Friedrich, D. Broughton, M. Houston, C.R. Shafran: Normative sexual behavior in children: A contemporary sample. Pediatrics 101:4 (April 1998). p. 9.

Objective. Sexual behavior in children can cause uncertainty in the clinician because of the relationship between sexual abuse and sexual behavior. Consequently, it is important to understand normative childhood sexual behavior.
Design. Sexual behavior in 1114 2- to 12-year-old children was rated by primary female caregivers. These children were screened for the absence of sexual abuse. A 38-item scale assessing a broad range of sexual behavior (Child Sexual Behavior Inventory, Third Version) was administered along with the Child Behavior Checklist and a questionnaire assessing family stress, family sexuality, social maturity of the child, maternal attitudes regarding child sexuality, and hours in day care.
Results. Sexual behavior was related to the child's age, maternal education, family sexuality, family stress, family violence, and hours/week in day care. Frequencies of sexual behaviors for 2- to 5-, 6- to 9-, and 10- to 12-year-old boys and girls are presented.
Conclusions. A broad range of sexual behaviors are exhibited by children who there is no reason to believe have been sexually abused. Their relative frequency is similar to two earlier studies, and this reinforces the validity of these results.
DD (gebaseerd op De Nieuwe Sekstant): Fenomenologie van sexueel gedrag bij kinderen van 2 tot 12 jaar. Sommige sexuele gedragingen komen veel voor bij kinderen, en moeten dan ook niet an sich als aanwijzing of bewijs voor sexueel misbruik worden gezien.

W.N. Friedrich, T.G.M. Sandfort, J. Oostveen, P.T. Cohen-Kettenis: Cultural differences in Sexual Behavior: 2-6 Year Old Dutch and American Children. Journal of Psychology & Human Sexuality 12:1/2 (2000), pp. 117-129.

Three samples, one American (N=500) and two from the Netherlands (N=460, N=297) of 2-6 year old children, screened for the absence of sexual abuse, were assessed with 25 items derived from the Child Sexual Behavior Inventory. Considerable differences existed between the three groups across a number of the behaviors rated, with a persisting tendency for the parents of the children from the Netherlands to report higher rates of sexual behavior. Family nudity was related to sexual behavior in all three samples. Althought the studies used an equivalent questionnaire and all three of the samples are predominantly middle class, the observed differences can be explained by methodological factors such as sample composition and the way data have been collected. The observed differences might, however, also reflect actual differences, and can be understood as resulting from cultural differences in sexual socialization. More rigorous research is needed to assess which explanation is most valid.
DD: In my opinion, the above abstract is too cautious. The main difference in sample composition (age) would have caused the two Dutch samples to differ in opposite directions, and while one Dutch sample is self-selected, the other is quite similar to the American one in the method of collection of participants.

B.H. Gundersen, J.E. Skår: Den Seksuelle Utvikling fra Fødsel til 3 års Alderen Belyst Gjennom Intervju med Foreldre og Dagheimspersonell. Research report, Department of Somatic Personality Psychology, University of Bergen, 1977.
B.H. Gundersen, P.S. Melås, J.E. Skår: Sexual Behavior of Preschool Children: Teachers' Observations. In: L.L. Constantine, F.M. Martinson (eds.): Children and Sex. New Findings, New Perspectives. Boston: Little, Brown & Co., 1981, pp. 45-61.

DD: 60 kindergarten teachers (57 male, 3 female) were asked about sexual behaviors of the children in their groups. Results:
58 felt that boys' behaviors differed from girls'. This difference was present at age 3, and grew larger with age. Boys were nosier, more vehement, more physically active, mostly playing with cars and weapons and building, aggressive, impudent and domineering. Girls were less physically and more amenable, mostly playing housekeeping and mother-girl with dolls, more affectionate, contact-seeking and ready to show their emotions.
Sexual words (e.g. names for genitals) were used "occasionally" according to half, and "often" or "very often" according to the other half of the teacher. For young children, the usage was innocent, for older children also provocative. Children from lower socio-economic background were more likely to know the vulgar words. Boys and girls used the same words, but boys more often.
Sexual questions were rare, and mostly on the subjects of pregnancy, childbirth and anatomical gender differences. Little or no pre-planned sexual education was given. Children seemed to be more interested in these subjects than their frequency of asking would indicate.
90% of the teachers answered that the children "often" or "very often" sought body contact, 20% stated that sometimes this took the form of exploration of the adult's body. Young children often searched contact irrespective of gender, but after the age of 4 boys' contact-seeking diminished, but girls' did not. The need for body contact in boys might take the form of half-serious fighting with other boys.
All interviewees had observed doctor/nurse/patient games and family roleplaying, 65% often or very often. 50% said that direct sexual behavior such as body exploration, genital manipulation and coitus-like behavior was involved. Teachers interfered only when objects were inserted in vagina or anus, or children were pushed to participate. The teachers stated that the mere nudity was also pleasurable to children.
Interest in own genitals was found by 94% of the teachers. 42% thought there were no gender differences, 47% that it occurred more with boys. Age differences were inconclusive.
Interest in other children's genitals occurred "sometimes" according to 64%, "often or "very often" according to 32%. Such interest was much greater among older children, and slightly greater among boys. Both genders were more interested in boys' than in girls' genitals.
Modesty was low, and more directed to peers than to adults. It was somewhat stronger in boys, and seemed to increase with age. There was not much shyness with playing naked, although some children never did so.
85% indicated that masturbation occurred; of these 1/4 said it occurred "often" or "very often", the rest "seldom" or "now and then". 23% had observed orgasm, 70% said that they did not know. There were large individual differences, with some children never masturbating and others a major part of the day. The much-masturbators often were isolating themselves during masturbation and/or showing behavior problems.
98% of the teachers sexual behavior in children was natural, as for its frequency 54% said "sometimes", 40% "often" or "very often", 3% "never".
Slightly more teachers reacted permissive than restrictive to children's sexuality. Presumably, the permissive group would be even greater if it were not for the idea that the parents would be negative towards such an attitude - an idea that might well be wrong.

H.M. Halverson: Genital and sphincter behavior of the male infant. Journal of Genetic Psychology 56 (1940), pp. 95-136.

Cite: In infants, Halverson demonstrated that boys showed a high degree of spontaneious erection during waking hours that declined as the child got older.

A.C. Kinsey, W.B. Pomeroy, C.E. Martin: Sexual Behavior in the Human Male. Philadelphia: Saunders, 1948.
A.C. Kinsey, W.B. Pomeroy, C.E. Martin, P. Gebhardt: Sexual Behavior in the Human Female. Philadelphia: Saunders, 1953.

Cite (Martinson): Infantile (and even prenatal) sensual behavior has been documented; it is now known, for example, that fetuses sometimes suck their thumbs, fingers, and toes, and that male babies are capable from birth of penile erections, and female babies of vaginal lubrication.
Idem: It seems quite safe to assert that the human child prior to puberty is capable of engaging in the same range of physiological sexual activities as the adult is capable of - a principle of general physical sexual-erotic capacity in children.
Idem: Kinsey (1953) reported one case of a 7-month old infant and five infants under 12 months old who were observed to masturbate.
Idem: Kinsey estimated that more than half of all boys could achieve orgasm at age 3 or 4, and almost all boys could do so three to five years before puberty. (Data on girls are not adequate to make such an estimate).

J.M. Kleeman: Genital self-stimulation in infant and toddler girls. In: I. Marcus, J. Francis (eds.): Masturbation from infancy to senescence, pp. 77-106. New York: International Universities Press, 1975.
A.W. Liley: The foetus as a personality. Australian-New Zealand Journal of Psychiatry 6 (1972), pp. 99-105.

Cite (Martinson): Infantile (and even prenatal) sensual behavior has been documented; it is now known, for example, that fetuses sometimes suck their thumbs, fingers, and toes, and that male babies are capable from birth of penile erections, and female babies of vaginal lubrication.

F. Lindblad, P.A. Gustafsson, I. Larsson, B. Lundin: Preschoolers' sexual behavior at daycare centers: an epidemiological study. Child Abuse & Neglect 19 (1995), pp. 569-577.

Cite (Friedrich): Swedish day care providers reported relatively low frequencies of intrusive and self-stimulating behaviors, a finding similar to research with the CSBI.

G. Neubauer: "Sex" im Kinderhaus: Auch kleine Jungen tun's!. In R. Winter (ed.): Stehversuche. Sexuelle Jungensozialisation und männliche Lebensbewältigung durch Sexualität. Tübingen: Neuling, 1993.
S. Phipps-Yonas, A. Yonas, M. Turner, M. Kamper: Sexuality in early childhood: the observations and opinions of family daycare providers. CURA Reporter 23 (1993), pp. 1-5.

Cite (Friedrich): Day care providers have been used as reporters in several studies. A sample of 564 day care providers was asked about the sexual behavior of 1- to 3- and 4- to 6-year-old children. The most consistent finding was age-related, with the youngest group, for example, judged to be the most comfortable with their own nudity. Day care providers reported that a majority of 4- to 6-year-olds interacted spontaneously, at least occasionally, in sexual ways. Children in this age range were also reported to have imitated sexual behaviors that they had seen demonstrated or had heard about.

M. Laan, J. Rademakers, C. Straver: De beleving van lichamelijkheid en intimiteit door kinderen. Kind en Adolescent 17:1 (1996), pp. 32-37.
J. Rademakers, M. Laan, C.J. Straver: Studying Children's Sexuality from the Child's Perspective. Journal of Psychology & Human Sexuality 12:1/2 (2000), pp. 49-60.

In an exploratory study on body awareness and experiences with physical intimacy from children's own perspective, 16 boys and 15 girls (age 8/9) were interviewed. Almost all children displayed a positive attitude towards intimate physical contact, especially cuddling. Half of the children didn't report experiences regarding sexuality or physical intimacy with peers, while one third displayed an active interest in these, had their own experiences and were able to reflect on those. A few children had a negative or ambivalent attitude towards physical intimacy. Data were also collected from one of the parents of each child. Parents presented a more positive an permissive view of the situation at home regarding physical intimacy than children did.
Discussion: It is obvious that physical intimacy means a great deal to these 8- and 9-year old boys and girls. Almost all children like to cuddle, most of them said they often wanted to cuddle with (one of) their parents. Nevertheless, some children stated this never happens. Another part of the children said they only cuddled with toys and animals, but never with people. Either parents underestimate their child's need for cuddling, or children underestimate the amount of physical contact between them and their parents. In general, parents presented a more positive and permissive view of the situation at home with regard to physical intimacy than the children did: more romping, more cuddling, more bathing together. Children may sketch a less positive situation because they feel shame or embarassment about these subjects. Even though the actual situation at home may be somewhat different, parents obviously regard being open, warm and permissive as the standard with regard to sex education and family relationships.
There are both similarities and differences beween children's sexuality as presented in this study and adolescent or adult sexuality. It seems that the sensations and behaviors which accompany the feeling of being in love don't change much over the years. The confusion and uncertainty which the children describe is similar to the state of mind adolescents and adults are usually in when they're in love. Also the body sensations, like blushing and tickling, are easily recognizable. Furthermore the ocmbination of being in love with fantasizing is common in both children and older people.
Another similarity between children and adolescents is the way in which the sexual development process seems to take place. What is obvious from the interviews with these 8- and 9-year old children is that also in this younger age group different phases of development can be distinguished. There is a big difference between the children who don't yet have an active interest and own experiences in this area, and the children who do. The transition from one phase to the second is presumably stimulated by their cognitive ability to reflect on their own behavior. From this moment on sexual development more and more becomes an active social learning process, whereas the experiences at a younger age are incorporated on a more intuitive and basic level.
A difference between children and adolescents and adults is that while older people seem to focus their sexual interest and behavior on specific body parts, such as bottom and genitals, children seem to have a less differentiated awareness of their body. Both with romping and with cuddling they use their whole body, and sensations they feel are not limited to sexual parts. We do know, from other studies, that young children have interest in each other's private parts. Probably, this is caused more by the fact that these are indeed parts which ar enot usually shown in public, and of which children sense that adults consider them special, than that this interest is the result of their own specific and sexual motivation.
DD: 31 kinderen van 8-9 jaar werden gevraagd over stoeien, knuffelen en verliefdheid - zowel of en met wie ze het deden als hoe ze erbij voelden. Een aantal andere gedragingen (bv. samen douchen) werd ook gevraagd. Ook werden ze gevraagd 'plezierige' en 'exciting' lichaamsdelen aan te geven.
Resultaten:
16 kinderen waren positief over fysiek contact, in het bijzonder knuffelen, maar weinig geinteresseerd in verliefdheid.
11 kinderen waren positief over fysiek contact zowel als over verliefdheid (deze groep zei i.h.a. dat ze al verliefd waren geweest, de eerste groep dat dat niet zo was).
4 kinderen gaven ontwijkende of sterk afwijkende antwoorden.
Plezierige/opwindende lichaamsdelen:

plezierigopwindend
hoofd/schouders2418
armen/benen1517
buik/rug1514
borststreek1113
genitaliën/kont710

Opvallend: Juist de lichaamsdelen die door volwassenen het meest intiem worden gevonden, zijn voor kinderen het minst plezierig/opwindend.
Ook de ouders werden ondervraagd; opvallend is dat de ouders aangaven dat gedragingen vaker plaatsvonden dan de kinderen. Aan de andere kant gaven veel meer kinderen dan ouders aan dat het kind vaak de behoefte had om te knuffelen met de ouders.

A. Rosenfeld, R. Bailey, B. Siegel, G. Bailey: Determining incestuous contact between parent and child: frequency of children touching parent's genitals in a nonclinical population. Journal of the American Academy of Child Psychiatry 25:4 (July 1986), pp. 481-484.

Cite (Friedrich): [P]arents reported that 30% to 45% of children under 10 years of age touched their mother's breasts or genitals at least once.
Cite: [O]ne study by Rosenfeld and colleagues, with a sample of 576 children aged 2-10, found that children touching parents' breasts or genitals was not uncommon on an incidental basis.

T.G.M. Sandfort, P.T. Cohen-Kettenis: Sexual Behavior in Dutch and Belgian Children as Observed by their Mothers. Journal of Psychology & Human Sexuality 12:1/2 (2000), pp. 105-115.

Mothers' observations (N=670) of child sexual behavior have been collected using an adapted version of the Child Sexual Behavior Inventory as developed by Friedrich et al. The ages of the boys (N=351) and girls (N=319) observed range from 0 to 11 years. The results show that there is a lot of variance in the frequency with which specific sexual behaviors are observed. The occurence of specific behaviors varies with age. While some behaviors are observed more frequently as the child gets older, others are observed less frequently. Boys and girls only differ in a few behaviors. The finding that the behavioral items form an internally consistent scale suggests that there is a general tendency to show sexually related behaviors, which is more or less strongly present in children, which might be a precursor of differential levels of sexual desires in adults.
DD: Results of a questionnaire, made by readers of Ouders van nu, to sexual behaviors of their children (ages 0-11, both genders). Children of sexually more permissive parents show more behaviors. Older children show more sexual behaviors, this result is opposite to those of earlier research. Reason is possibly a different choice of behaviors that are checked. Differences between boys and girls are usually small.
Table of results (percentages):

Item (abbreviated)TotalBoysGirlsr-age
SEXUAL BEHAVIORS
Touches own sexual parts97***9896-.06
Touches breasts777479-.16***
Interested in opposite sex656566.12**
Plays doctor60***5565.21***
Asks questions about sexuality535156.54***
Masturbates with hand50***5939 .09
Tries to look at people undressing434344 .00
Touches others' sex parts333036-.10
Undresses other people252228-.12**
Shows sex parts to adults212517.03
Shows sex parts to children212418 .10
Masturbates with object16**1220-.06
Looks at nude pictures161813 .29***
French kissing151514 -.03
Hugs unfamiliar adults151713-.11**
Draws sex parts131116 .34***
Uses sexual words111111 .40***
Rubs body against people101110-.06
Talks flirtatiously10812 .05
Talks about sexual acts 8 9 8 .35***
Inserts objects in vagina/anus 4*** 1 7-.03
Makes sexual sounds 4 3 4-.01
Asks to engage in sex acts 3 33.03
Imitates sexual behavior with dolls 2** 1 4-.01
Asks to watch explicit tv 1 1 2.28***
GENDER ATYPICAL BEHAVIORS
Wants to be of the opposite sex101010 .02
Pretends to be of the opposite sex201921 .05
Plays with typical boy toys92***9788 .01
Plays with typical girl toys75***6092 .01

Asterisks indicate significant differences between boys and girls (column 'Total') or significant dependency on age (r-age) - **: p<.01, ***: p<.001.

E. Schoentjes, D. Deboutte, W. Friedrich: Child Sexual Behavior Inventory: A Dutch-speaking Normative Sample. Pediatrics 104:4 (October 1999), pp. 885-893.

Objectives. To describe normative sexual behavior in Dutch-speaking children; to assess the frequencies of different types of sexual behaviors reported in children by their parents; to analyze the relation of these sexual behaviors to demographic, personal, familial, and general behavioral variables; and to compare the Dutch-speaking sample with American samples.
Method. Nine hundred seventeen children (2-12 years of age), screened to exclude sexual abuse, were rated by their caregiver via parent report consisting of the translated Dutch version of the Child Sexual Behavior Inventory, the Child Behavior Checklist, a life event checklist, and a questionnaire assessing family nudity and parental attitudes regarding sexuality.
Results. Frequencies of a wide variety of sexual behaviors for 2- to 5-, 6- to 9-, and 10- to 12-year-old children are presented. Sexual behavior was found to be related to the child's age, maternal education, family nudity, and parental attitudes toward sexuality. The positive relation to general behavioral problems was confirmed. Findings were primarily similar to previously published American studies.
Conclusion. Our study confirms that sexual behavior in children is varied and related to developmental, personal, and familial factors. The relative frequency of the wide variety of sexual behaviors in a Dutch-speaking normative sample is comparable to American samples.