Anchoring has little effect when forming first impressions of facial attractiveness.

First impressions based on facial appearance affect our behaviour towards others. Since the same face will appear different across images, over time, and so on, our impressions may not be equally weighted across exposures but are instead disproportionately influenced by earlier or later instances. Here, we followed up on previous work which identified an anchoring effect, whereby higher attractiveness ratings were given to a person after viewing naturally varying images of their face presented in descending (high-to-low), rather than ascending (low-to-high), order of attractiveness of these images. In Experiment 1 (n = 301), we compared these 'descending' and 'ascending' conditions for unfamiliar identities by presenting six-image sequences. Although we found higher attractiveness ratings for the 'descending' condition, this small effect equated to only 0.22 points on a 1-7 response scale. In Experiment 2 (n = 307), we presented these six-image sequences in a random order and found no difference in attractiveness ratings given to these randomly ordered sequences when compared with those resulting from both our 'descending' and 'ascending' conditions. Further, we failed to detect an influence of the earlier images in these random sequences on attractiveness ratings. Taken together, we found no compelling evidence that anchoring could have an effect on real-world impression formation.

The psychometrics of rating facial attractiveness using different response scales.

Perceiving facial attractiveness is an important behaviour across psychological science due to these judgments having real-world consequences. However, there is little consensus on the measurement of this behaviour, and practices differ widely. Research typically asks participants to provide ratings of attractiveness across a multitude of different response scales, with little consideration of the psychometric properties of these scales. Here, we make psychometric comparisons across nine different response scales. Specifically, we analysed the psychometric properties of a binary response, a 0-100 scale, a visual analogue scale, and a set of Likert scales (1-3, 1-5, 1-7, 1-8, 1-9, 1-10) as tools to measure attractiveness, calculating a range of commonly used statistics for each. While certain properties suggested researchers might choose to favour the 1-5, 1-7 and 1-8 scales, we generally found little evidence of an advantage for one scale over any other. Taken together, our investigation provides consideration of currently used techniques for measuring facial attractiveness and makes recommendations for researchers in this field.

Personal radiofrequency electromagnetic field exposure of adolescents in the Greater London area in the SCAMP cohort and the association with restrictions on permitted use of mobile communication technologies at school and at home.

Personal measurements of radiofrequency electromagnetic fields (RF-EMF) have been used in several studies to characterise personal exposure in daily life, but such data are limitedly available for adolescents, and not yet for the United Kingdom (UK). In this study, we aimed to characterise personal exposure to RF-EMF in adolescents and to study the association between exposure and rules applied at school and at home to restrict wireless communication use, likely implemented to reduce other effects of mobile technology (e.g. distraction). We measured exposure to RF-EMF for 16 common frequency bands (87.5 MHz-3.5 GHz), using portable measurement devices (ExpoM-RF), in a subsample of adolescents participating in the cohort Study of Cognition, Adolescents and Mobile Phones (SCAMP) from Greater London (UK) (n = 188). School and home rules were assessed by questionnaire and concerned the school's availability of WiFi and mobile phone policy, and parental restrictions on permitted mobile phone use. Adolescents recorded their activities in real time using a diary app on a study smartphone, while characterizing their personal RF-EMF exposure in daily life, during different activities and times of the day. Data analysis was done for 148 adolescents from 29 schools who recorded RF-EMF data for a median duration of 47 h. The majority (74%) of adolescents spent part of their time at school during the measurement period. Median total RF-EMF exposure was 40 µW/m2 at home, 94 µW/m2 at school, and 100 µW/m2 overall. In general, restrictions at school or at home made little difference for adolescents' measured exposure to RF-EMF, except for uplink exposure from mobile phones while at school, which was found to be significantly lower for adolescents attending schools not permitting phone use at all, compared to adolescents attending schools allowing mobile phone use during breaks. This difference was not statistically significant for total personal exposure. Total exposure to RF-EMF in adolescents living in Greater London tended to be higher compared to exposure levels reported in other European countries. This study suggests that school policies and parental restrictions are not associated with a lower RF-EMF exposure in adolescents.

Relationship between Stunting, Wasting, Underweight and Geophagy and Cognitive Function of Children.

OBJECTIVES: The aim of this study was to investigate the relationship between anthropometric characteristics and both geophagy and cognitive function of children. STUDY DESIGN: The study prospectively followed singleton children whose mothers participated in the MiPPAD clinical trial in Allada, Benin, from birth to age 12 months. Anthropometric measurements were taken at birth and 9 and 12 months. Wasting, stunting and underweight were defined as weight-for-length, length-for-age and weight-for-age Z-scores less than -2, respectively. Cognitive and motor functions were assessed using the Mullen Scales of Early Learning. Parent-reported geophageous habits of children were collected when the children were 12 months. Multiple linear and logistic regressions were used to analyse the data. RESULTS: A total of 632 children (49.7% girls) were involved in the study. Stunting, wasting and underweight were observed in 14.1%, 13.6% and 17.7%, respectively, at 9 months and 17.3%, 12.7% and 17.2%, respectively, at 12 months. The prevalence of geophagy among the children was 48.2%. Impaired growth at 9 and 12 months was consistently associated with low cognitive and gross motor (GM) score. Children stunted at 9 months had lower GM scores at 12 months compared with their non-stunted peers (ß = -3.48, 95% confidence interval -6.62 to -0.35). CONCLUSIONS: Stunting, wasting and underweight are associated with cognitive and GM deficits in infants. In this setting, impaired growth was not associated with geophagy. Further research evaluating geophagy and growth prospectively and concurrently from birth to 36 months is needed.

Consequences of prenatal geophagy for maternal prenatal health, risk of childhood geophagy and child psychomotor development.

OBJECTIVE: To investigate the relationship between prenatal geophagy, maternal prenatal haematological indices, malaria, helminth infections and cognitive and motor development among offspring. METHODS: At least a year after delivery, 552 of 863 HIV-negative mothers with singleton births who completed a clinical trial comparing the efficacy of sulfadoxine-pyrimethamine and mefloquine during pregnancy in Allada, Benin, responded to a nutrition questionnaire including their geophagous habits during pregnancy. During the clinical trial, helminth infection, malaria, haemoglobin and ferritin concentrations were assessed at 1st and 2nd antenatal care visits (ANV) and at delivery. After the first ANV, women were administered daily iron and folic acid supplements until three what? post-delivery. Singleton children were assessed for cognitive function at age 1 year using the Mullen Scales of Early Learning. RESULTS: The prevalence of geophagy during pregnancy was 31.9%. Pregnant women reporting geophagy were more likely to be anaemic (AOR = 1.9, 95% CI [1.1, 3.4]) at their first ANV if they reported geophagy at the first trimester. Overall, prenatal geophagy was not associated with maternal haematological indices, malaria or helminth infections, but geophagy during the third trimester and throughout pregnancy was associated with poor motor function (AOR = -3.8, 95% CI [-6.9, -0.6]) and increased odds of geophagous behaviour in early childhood, respectively. CONCLUSIONS: Prenatal geophagy is not associated with haematological indices in the presence of micronutrient supplementation. However, it may be associated with poor child motor function and infant geophagy. Geophagy should be screened early in pregnancy.

Total recall in the SCAMP cohort: Validation of self-reported mobile phone use in the smartphone era.

Mobile phone use, predominantly smartphones, is almost ubiquitous amongst both adults and children. However adults and children have different usage patterns. A major challenge with research on mobile phone use is the reliability of self-reported phone activity for accurate exposure assessment. We investigated the agreement between self-reported mobile phone use data and objective mobile operator traffic data in a subset of adolescents aged 11-12 years participating in the Study of Cognition, Adolescents and Mobile Phones (SCAMP) cohort. We examined self-reported mobile phone use, including call frequency, cumulative call time duration and text messages sent among adolescents from SCAMP and matched these data with records provided by mobile network operators (n = 350). The extent of agreement between self-reported mobile phone use and mobile operator traffic data use was evaluated using Cohen's weighted Kappa (ĸ) statistics. Sensitivity and specificity of self-reported low (< 1 call/day, ≤ 5min of call/day or ≤ 5 text messages sent/day) and high (≥ 11 calls/day, > 30min of call/day or ≥ 11 text messages sent /day) use were estimated. Agreement between self-reported mobile phone use and mobile operator traffic data was highest for the duration spent talking on mobile phones per day on weekdays (38.9%) and weekends (29.4%) compared to frequency of calls and number of text messages sent. Adolescents overestimated their mobile phone use during weekends compared to weekdays. Analysis of agreement showed little difference overall between the sexes and socio-economic groups. Weighted kappa between self-reported and mobile operator traffic data for call frequency during weekdays was κ = 0.12, 95% CI 0.06-0.18. Of the three modes of mobile phone use measured in the questionnaire, call frequency was the most sensitive for low mobile phone users on weekdays and weekends (77.1, 95% CI: 69.3-83.7 and 72.0, 95% CI: 65.0-78.4, respectively). Specificity was moderate to high for high users with the highest for call frequency during weekdays (98.4, 95% CI: 96.4-99.5). Despite differential agreement between adolescents' self-reported mobile phone use and mobile operator traffic data, our findings demonstrate that self-reported usage adequately distinguishes between high and low use. The greater use of mobile smartphones over Wi-Fi networks by adolescents, as opposed to mobile phone networks, means operator data are not the gold standard for exposure assessment in this age group. This has important implications for epidemiologic research on the health effects of mobile phone use in adolescents.

Metacognition during unfamiliar face matching.

Kruger and Dunning (1999) described a metacognitive bias in which insight into performance is linked to competence: poorer performers are less aware of their mistakes than better performers. Competence-based insight has been argued to apply generally across task domains, including a recent report investigating social cognition using a variety of face-matching tasks. Problematically, serious statistical and methodological criticisms have been directed against the traditional method of analysis used by researchers in this field. Here, we further illustrate these issues and investigate new sources of insight within unfamiliar face matching. Over two experiments (total N = 1077), where Experiment 2 was a preregistered replication of the key findings from Experiment 1, we found that insight into performance was multi-faceted. Participants demonstrated insight which was not based on competence, in the form of accurate updating of estimated performance. We also found evidence of insight which was based on competence: the difference in confidence on correct versus incorrect trials increased with competence. By providing ways that we can move beyond problematic, traditional approaches, we have begun to reveal a more realistic story regarding the nature of insight into face perception.

Bidirectional associations between sleep problems and behavioural difficulties and health-related quality of life in adolescents: Evidence from the SCAMP longitudinal cohort study.

Background: Sleep problems show associations with negative outcomes in both physical and mental health in adolescents, but the associations may be reciprocal. We aimed to assess bidirectional associations between sleep problems and mental health symptoms including behavioural difficulties (internalising and externalising difficulties) and low health-related quality of life (HRQoL). Methods: A total of 6616 adolescents (52.4% females) across Greater London completed baseline assessments when they were aged 11-12 years, and 3803 of them (57.2% females) completed follow-up assessments at aged 13-15 years. Weekday and weekend sleep duration were derived from self-reported bedtime, sleep onset latency and wake time. Sleep disturbance was assessed using a standardized sleep disturbance scale. Internalising and externalising difficulties were assessed using subscales of the Strength and Difficulties Questionnaire. HRQoL was assessed using the KIDSCREEN-10 questionnaire. Cross-lagged structural equation modelling was used with multiple imputation to examine bidirectional associations between sleep problems and mental health symptoms. Results: Females had greater internalising difficulties, worse HRQoL and more sleep disturbance than males. Persistent insufficient weekday and weekend sleep, and sleep disturbance (i.e., at both baseline and follow-up) were associated with internalising and externalising difficulties and low HRQoL at follow-up (ORs ranged from 1.53 to 3.63). Persistent externalising difficulties and low HRQoL were also associated with insufficient weekend sleep and sleep disturbance at follow-up (ORs ranged from 1.68 to 4.25). Using continuous variables, we found bidirectional associations between weekday sleep duration and HRQoL, weekend sleep duration and externalising score, sleep quality and internalising score, and sleep quality and HRQoL. The association magnitudes were mostly similar in the two directions. Conclusions: Our study showed bidirectional associations between sleep problems and mental health symptoms during adolescence, indicating that early intervention and treatment on the first-occurring symptom may prevent the development of subsequent problems.

Waking Activities and Sleep: Analysis of United Kingdom Adolescents' Daily Time-Use Diaries.

PURPOSE: To investigate waking activities associated with risks of short and long sleep in a representative cohort of UK adolescents. METHODS: Data from 14-year-olds participating in the UK Millennium Cohort Study were used. Daily time-use diaries were completed by adolescents on two randomly selected days (one weekday and one weekend) to capture their activities within a 24-hour period from 4 a.m. of each selected day. Short and long sleep duration categories were defined as beyond the extreme lower and upper thresholds of acceptable age-specific sleep durations recommended by the National Sleep Foundation, respectively. RESULTS: Approximately 8% and 6% were short sleepers on weekdays and weekends, respectively. On average, adolescents spent 33% of their time awake per weekend day on recreational digital media activities. Compared with those who had optimal sleep on weekdays, short sleepers spent more time on personal care (mean difference = +56 minutes; 95% confidence interval [CI]: 21; 92) and less time on exercise activities (mean difference = -15 minutes; 95% CI: -27; -3). Ten-minute increase in daily digital media activity was associated with 2% (95% CI: 1.01; 1.03) higher relative risk of adolescents being short sleepers on weekdays. Relative risk of short sleeping was 1.03 (95% CI: 1.01; 1.04) times higher for every10-minute daily increase in travel time on weekdays. CONCLUSIONS: Adolescents spend up to one-third of their time awake per day on digital media. However, more time spent on personal care and travel on weekdays and weekends is associated with increased risk of short sleep. These findings permit a reflection on appropriate interventions needed to improve sleep duration in sleep-deprived teens.

Lecture start time and sleep characteristics: Analysis of daily diaries of undergraduate students from the LoST-Sleep project.

OBJECTIVES: Emerging evidence shows that later high school start times are associated with increased sleep duration; however, little is known if this extends to the university setting. This study investigated associations of first lecture start times with sleep characteristics among university students. DESIGN: Daily diaries. SETTING: Lincoln, UK. PARTICIPANTS: One hundred and fifty-five undergraduate students completed 7-night sleep diaries MEASUREMENTS: Of the plausible lecture-day diaries (Monday-to-Friday, expected N = 755 days), 567 days were lecture days (M = 3.8 lecture-days per student, SD = 1.1). The Consensus Sleep Diary was used to collect sleep characteristics. Two-level multilevel mixed effect generalized linear models were employed in the analyses. RESULTS: Seventy-five percent of first lectures occurred before noon. Students reported short sleep (M = 7.0 hours, SD = 1.9) and fewer reported highest levels of sleep quality (42.8%) and restfulness (24.8%) when first lectures started at 09:00 or 09:30 compared to 10:00 or later. Every hour delay of first lecture start time was associated with 15.1 (95% confidence interval [CI]: 9.5; 20.7) minutes increase in sleep duration and higher odds of reporting the highest levels of sleep quality and restfulness. Focusing on attended lectures starting before noon, hourly delay of first lecture start time was associated with 37.4 (95% CI: 22.0; 52.8) minutes increased sleep duration. Bedtime, sleep time, and sleep onset latency were not significantly associated with first lecture start times. CONCLUSION: This study found that undergraduate students had longer sleep and healthier sleep quality when university first lectures started later. The earliest lecture start time that afforded sufficient sleep duration for students was 10:00.

Mindfulness Meditation Improves Visual Short-Term Memory.

Research into the effects of mindfulness meditation on behavioral outcomes has received much interest in recent years, with benefits for both short-term memory and working memory identified. However, little research has considered the potential effects of brief mindfulness meditation interventions or the nature of any benefits for visual short-term memory. Here, we investigate the effect of a single, 8-minute mindfulness meditation intervention, presented via audio recording, on a short-term memory task for faces. In comparison with two control groups (listening to an audiobook or simply passing the time however they wished), our mindfulness meditation participants showed greater increases in visual short-term memory capacity from pre- to post-intervention. In addition, only mindfulness meditation resulted in significant increases in performance. In conclusion, a single, brief mindfulness meditation intervention led to improvements in visual short-term memory capacity for faces, with important implications regarding the minimum intervention necessary to produce measurable changes in short-term memory tasks.

Face averages and multiple images in a live matching task.

We know from previous research that unfamiliar face matching (determining whether two simultaneously presented images show the same person or not) is very error-prone. A small number of studies in laboratory settings have shown that the use of multiple images or a face average, rather than a single image, can improve face matching performance. Here, we tested 1,999 participants using four-image arrays and face averages in two separate live matching tasks. Matching a single image to a live person resulted in numerous errors (79.9% accuracy across both experiments), and neither multiple images (82.4% accuracy) nor face averages (76.9% accuracy) improved performance. These results are important when considering possible alterations which could be made to photo-ID. Although multiple images and face averages have produced measurable improvements in performance in recent laboratory studies, they do not produce benefits in a real-world live face matching context.

Face morphing attacks: Investigating detection with humans and computers.

BACKGROUND: In recent years, fraudsters have begun to use readily accessible digital manipulation techniques in order to carry out face morphing attacks. By submitting a morph image (a 50/50 average of two people's faces) for inclusion in an official document such as a passport, it might be possible that both people sufficiently resemble the morph that they are each able to use the resulting genuine ID document. Limited research with low-quality morphs has shown that human detection rates were poor but that training methods can improve performance. Here, we investigate human and computer performance with high-quality morphs, comparable with those expected to be used by criminals. RESULTS: Over four experiments, we found that people were highly error-prone when detecting morphs and that training did not produce improvements. In a live matching task, morphs were accepted at levels suggesting they represent a significant concern for security agencies and detection was again error-prone. Finally, we found that a simple computer model outperformed our human participants. CONCLUSIONS: Taken together, these results reinforce the idea that advanced computational techniques could prove more reliable than training people when fighting these types of morphing attacks. Our findings have important implications for security authorities worldwide.

Processed data on the night-time use of screen-based media devices and adolescents' sleep quality and health-related quality of life.

The data presented in this article relate to the research article entitled "Night-time screen-based media device use and adolescents' sleep and health-related quality of life". The present data reports findings from the investigation of the relationship between night-time screen-based media devices (SBMD) use and both sleep quality and health-related quality of life (HRQoL) among 11 to 12-year-olds. Baseline data from a large cohort of 6,616 adolescents from 39 schools in and around London, UK, participating in the Study of Cognition Adolescents and Mobile Phone (SCAMP) were analysed. Self-report data on adolescents' use of any SBMD (mobile phone, tablet, laptop, television etc.) were the main exposures of interest. Mobile phone and television were the most commonly used portable and non-portable device, respectively. Sleep variables were derived from self-reported weekday and/or weekend bedtime, sleep onset latency (SOL) and wake time. Sleep quality was assessed using four standardised dimensions from the Swiss Health Survey. HRQoL was estimated using the KIDSCREEN-10 questionnaire.

Night-time screen-based media device use and adolescents' sleep and health-related quality of life.

OBJECTIVE: The present study investigates the relationship between night-time screen-based media devices (SBMD) use, which refers to use within 1 h before sleep, in both lit and dark rooms, and sleep outcomes and health-related quality of life (HRQoL) among 11 to 12-year-olds. METHODS: We analysed baseline data from a large cohort of 6616 adolescents from 39 schools in and around London, United Kingdom, participating in the Study of Cognition Adolescents and Mobile Phone (SCAMP). Adolescents self-reported their use of any SBMD (mobile phone, tablet, laptop, television etc.). Sleep variables were derived from self-reported weekday and/or weekend bedtime, sleep onset latency (SOL) and wake time. Sleep quality was assessed using four standardised dimensions from the Swiss Health Survey. HRQoL was estimated using the KIDSCREEN-10 questionnaire. RESULTS: Over two-thirds (71.5%) of adolescents reported using at least one SBMD at night-time, and about a third (32.2%) reported using mobile phones at night-time in darkness. Night-time mobile phone and television use was associated with higher odds of insufficient sleep duration on weekdays (Odds Ratio, OR = 1.82, 95% Confidence Interval, CI [1.59, 2.07] and OR = 1.40, 95% CI [1.23, 1.60], respectively). Adolescents who used mobile phones in a room with light were more likely to have insufficient sleep (OR = 1.32, 95% CI [1.10, 1.60]) and later sleep midpoint (OR = 1.64, 95% CI [1.37, 1.95]) on weekends compared to non-users. The magnitude of these associations was even stronger for those who used mobile phones in darkness for insufficient sleep duration on weekdays (OR = 2.13, 95% CI [1.79, 2.54]) and for later sleep midpoint on weekdays (OR = 3.88, 95% CI [3.25, 4.62]) compared to non-users. Night-time use of mobile phones was associated with lower HRQoL and use in a dark room was associated with even lower KIDSCREEN-10 score (ß = -1.18, 95% CI [-1.85, -0.52]) compared to no use. CONCLUSIONS: We found consistent associations between night-time SBMD use and poor sleep outcomes and worse HRQoL in adolescents. The magnitude of these associations was stronger when SBMD use occurred in a dark room versus a lit room.

Prenatal Iron Deficiency, Neonatal Ferritin, and Infant Cognitive Function.

OBJECTIVE: To investigate the impact of prenatal maternal iron deficiency (ID) on cord blood serum ferritin (CBSF) concentration and infant cognitive and motor development. METHODS: Our prospective cohort study included 636 mother-singleton child pairs from 828 eligible pregnant women who were enrolled during their first antenatal care (ANC) visit in Allada, Benin, into a clinical trial comparing the efficacy of mefloquine and sulfadoxine-pyrimethamine. Venous blood samples of women were assessed for ferritin and hemoglobin concentrations at the first and second ANC visits (occurring at least 1-month apart) and at delivery. Women were prescribed daily iron and folic acid supplements throughout pregnancy. Hematologic examinations were repeated for cord blood at birth. At age 1 year, cognitive and motor functions of children were assessed by using the Mullen Scales of Early Learning. RESULTS: The prevalence of prenatal ID at first and second ANC visits, and at delivery was 30.5%, 34.0%, and 28.4%, respectively. CBSF concentrations were similar between ID and non-ID pregnant women. Neither prenatal ID nor CBSF concentration was associated with poor cognitive or gross motor function of children at age 1 year. CBSF concentrations were lower among mothers who had ID anemia (IDA) at delivery compared with non-IDA pregnant women (adjusted mean difference: -0.2 [95% confidence interval: -0.4 to -0.0]). CONCLUSIONS: In a malaria-endemic region, ID in pregnancy in the context of iron supplementation is neither associated with CBSF concentration nor with infant cognitive and motor development. Prenatal IDA around the time of delivery is associated with lower CBSF concentrations.

Impact of helminth infection during pregnancy on cognitive and motor functions of one-year-old children.

OBJECTIVE: To determine the effect of helminth infection during pregnancy on the cognitive and motor functions of one-year-old children. METHODS: Six hundred and thirty five singletons born to pregnant women enrolled before 29 weeks of gestation in a trial comparing two intermittent preventive treatments for malaria were assessed for cognitive and motor functions using the Mullen Scales of Early Learning, in the TOVI study, at twelve months of age in the district of Allada in Benin. Stool samples of pregnant women were collected at recruitment, second antenatal care (ANC) visit (at least one month after recruitment) and just before delivery, and were tested for helminths using the Kato-Katz technique. All pregnant women were administered a total of 600 mg of mebendazole (100 mg two times daily for 3 days) to be taken after the first ANC visit. The intake was not directly observed. RESULTS: Prevalence of helminth infection was 11.5%, 7.5% and 3.0% at first ANC visit, second ANC visit and at delivery, respectively. Children of mothers who were infected with hookworms at the first ANC visit had 4.9 (95% CI: 1.3-8.6) lower mean gross motor scores compared to those whose mothers were not infected with hookworms at the first ANC visit, in the adjusted model. Helminth infection at least once during pregnancy was associated with infant cognitive and gross motor functions after adjusting for maternal education, gravidity, child sex, family possessions, and quality of the home stimulation. CONCLUSION: Helminth infection during pregnancy is associated with poor cognitive and gross motor outcomes in infants. Measures to prevent helminth infection during pregnancy should be reinforced.

Prenatal Hemoglobin Levels and Early Cognitive and Motor Functions of One-Year-Old Children.

OBJECTIVE: To explore the relationship between prenatal hemoglobin (Hb) concentration and infant cognitive and motor functions. METHODS: Our prospective cohort study included 1-year-old children born to women enrolled at their first antenatal care (ANC) visit in Allada, Benin, before 29 weeks of pregnancy, within a trial comparing the efficacy of sulfadoxine-pyrimethamine and mefloquine. Hb concentrations of pregnant women were determined from venous blood samples collected at first and second ANC visits of at least 1-month interval and at delivery. Women were prescribed oral iron, folic acid, and anthelminthics after the first ANC visit. A total of 636 children (76.8% of eligible children) were assessed by trained research nurses for cognitive and motor functions by using the Mullen Scales of Early Learning. RESULTS: Prevalence of anemia (Hb < 110 g/L) decreased from 67.0% at first ANC visit (mean gestational age [SD], 22.1 [4.0] weeks) to 38.4% at delivery. Mean (SD) Hb concentrations increased from 103.7 (12.3) at first ANC visit to 112.4 (14.1) at delivery. We observed a significant negative quadratic relationship between infant gross motor (GM) function and Hb concentration at first and second ANC visits. Thus, infant GM scores increased sharply with increasing maternal Hb concentration until 90 g/L where increasing GM was mild, and began to decline after 110 g/L. CONCLUSIONS: There appears to be an Hb concentration range that may be optimal for GM function of 1-year-old children. This may reflect the importance of physiologic hemodilution, which occurs after the second trimester until 34 weeks of gestation.