Why does head form change in children of immigrants? A reappraisal.

OBJECTIVES: We test two specific hypotheses that explain the cranial changes Boas observed in Hebrews and Sicilians, namely that Hebrew change results from abandoning cradling of infants in America, while in Sicilians it results from impaired growth in America. METHODS: Boas's (1928) data were used to test these hypotheses. The role of cradling in cranial shape was examined by comparing cranial indices of U.S.-born and foreign children between 1.5 and 5 years of age. Age changes in cranial index of Hebrew and Sicilian children ages five to eighteen were examined to demonstrate differing patterns of age changes, which could be explained by environmental differences. Statistical methods employed were t-tests, least squares, and loess regression. RESULTS: The difference between American and foreign-born Hebrew children arose prior to five years of age, after which it remained constant. American and foreign-born Sicilians, on the other hand, had similar cranial indices at age five, and diverged during the growing years, primarily because American-born children did not exhibit the reduction in cranial index with age seen in the other groups. CONCLUSIONS: The results support the two hypotheses tested. Change in Hebrew cranial indices resulted from abandoning the practice of cradling infants in America. U.S.-born Sicilian children experienced an environment worse than the one in Europe, and consequently experienced impaired growth. We conclude that the changes Boas observed resulted from specific behavioral and economic conditions unique to each group, rather than a homogeneous American environment.

Prevalence of endoparasitic infection in children and its relation with cholera prevention efforts in Mexico.

OBJECTIVE: To investigate whether increased knowledge and use of public health measures promoted for cholera prevention is reflected in lower prevalence of parasitic infection in households in a community in the state of Tamaulipas, Mexico, that is close to the border with the United States of America. METHODS: Between 1994 and 1997, fecal samples from 438 children were collected through convenience sampling and then examined for helminth eggs/larvae and protozoan cysts as biologic indicators of household compliance with recommended cholera prevention measures. The suggested measures were to wash hands before meals and after defecation, to drink purified water, to wash fruits and vegetables, and to eat well-cooked food. In addition, information on the knowledge of and the use of cholera preventive measures was collected by interviews with adult informants in 252 households (186 of those households also provided a fecal sample for analysis). RESULTS: Parasitic infections occurred in 131 of the 438 children (30%), who resided in 79 of the 186 households (42%) that provided fecal samples. Giardia lamblia accounted for 12.5% of all infections. Infections with Hymenolepis nana, Ascaris lumbricoides, Trichuris trichiura, Enterobius vermicularis, Ancylostoma/Necator, Strongyloides stercoralis, Entamoeba coli, Entamoeba hartmanni, Entamoeba histolytica, Endolimax nana, and Iodamoeba bütschlii were also noted. Infected children were older and more often had an infected sibling. Households with three or more children were also more likely to have an infected child. The primary caregivers in the households where at least one child had a parasitic infection were distinguished by their inability to list at least three cholera prevention measures from memory. CONCLUSIONS: The 42% household prevalence of parasitic infection was relatively high and indicates that some residents of this community may not have fully embraced the public health education efforts promoted for prevention of cholera. The occurrence of nonpathogenic protozoan parasites such as Endolimax nana, Entamoeba coli, Entamoeba hartmanni, and I. bütschlii are important bioindicators for the persistence of unhygienic behaviors that increase the risk of cholera and other infectious diseases dependent on fecal-oral transmission. Information obtained by similar studies can be useful for monitoring compliance with community health and hygiene programs and may indicate the need to intensify educational efforts for the prevention of diarrhea associated with enteric pathogens that cannot be controlled by drugs alone.

Prevalence of endoparasitic infection in children and its relation with cholera prevention efforts in Mexico

OBJECTIVE: To investigate whether increased knowledge and use of public health measures promoted for cholera prevention is reflected in lower prevalence of parasitic infection in households in a community in the state of Tamaulipas, Mexico, that is close to the border with the United States of America. METHODS: Between 1994 and 1997, fecal samples from 438 children were collected through convenience sampling and then examined for helminth eggs/larvae and protozoan cysts as biologic indicators of household compliance with recommended cholera prevention measures. The suggested measures were to wash hands before meals and after defecation, to drink purified water, to wash fruits and vegetables, and to eat well-cooked food. In addition, information on the knowledge of and the use of cholera preventive measures was collected by interviews with adult informants in 252 households (186 of those households also provided a fecal sample for analysis). RESULTS: Parasitic infections occurred in 131 of the 438 children (30 percent), who resided in 79 of the 186 households (42 percent) that provided fecal samples. Giardia lamblia accounted for 12.5 percent of all infections. Infections with Hymenolepis nana, Ascaris lumbricoides, Trichuris trichiura, Enterobius vermicularis, Ancylostoma/Necator, Strongyloides stercoralis, Entamoeba coli, Entamoeba hartmanni, Entamoeba histolytica, Endolimax nana, and Iodamoeba bütschlii were also noted. Infected children were older and more often had an infected sibling. Households with three or more children were also more likely to have an infected child. The primary caregivers in the households where at least one child had a parasitic infection were distinguished by their inability to list at least three cholera prevention measures from memory. CONCLUSIONS: The 42 percent household prevalence of parasitic infection was relatively high and indicates that some residents of this community may not have fully embraced the public health education efforts promoted for prevention of cholera. The occurrence of nonpathogenic protozoan parasites such as Endolimax nana, Entamoeba coli, Entamoeba hartmanni, and I. bütschlii are important bioindicators for the persistence of unhygienic behaviors that increase the risk of cholera and other infectious diseases dependent on fecal-oral transmission...

An evolutionary perspective on maladaptive traits and cultural conformity.

The problem of maladaptive cultural traits is explored through the notion of adaptive psychological mechanisms. It is suggested that the theory of a specific conformity mechanism is plausible, supported by multidisciplinary data, and helpful in explaining the proliferation and persistence of human maladaptive behavior. © 1996 Wiley-Liss, Inc.