Babies' Expectations About Racial Interactions: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Babies' Expectations About Racial Interactions (NCT05324007), a randomized na study. The primary outcome is Participants' Average Time Spent Looking at Stimuli According to Condition.

2. Clinical Question

3. Trial Design

The registry describes a randomized, quadruple-masked, parallel study. It labels the study phase as not applicable and the status as completed. The record gives a start date of 2021-09-01 and a primary completion date of 2022-03-27. The sponsor is the University of Chicago. The listed condition names are White-White, Black-Black, and Black-White.

The procedure described for the White-White condition begins with 4 familiarization trials. Two adults take turns waving and saying a short sentence; each trial lasts 10.5s. Which adult speaks first and which side she appears on are counterbalanced. The Black-Black and Black-White descriptions say that the procedure is identical apart from the racial pairing of the adults. The description of the White-White procedure is cut off in the registry record, so details beyond the text recorded there are not available. The study is described as lasting about 10 minutes.

Random allocation can reduce systematic differences between conditions on average, while a parallel design means participants are assigned to a condition rather than moving through each condition. Those are general features of these design labels; the registry record does not report the allocation sequence, how allocation was concealed, or the roles covered by quadruple masking. It also does not specify which study personnel or family members were masked. The meaning of the masking label should therefore not be extended beyond what the registry states.

This is a basic-science study of infants’ social expectations, not a trial comparing treatments or clinical management strategies. The registry record does not report a protocol rationale for its design, a sample-size justification, or an account of interim analyses.

4. Participant Flow and Accounting

The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.

Before assignment: No participants were excluded before assignment to arm.

Overall Study

Analysis population for the primary outcome, as defined in the registry: We ended up excluding 38 infants from the 128 infants we recruited due to technical issues (e.g., no video of infant in the study produced or infants' study video was cut off due to internet speed), parental/family interference (e.g., parents spoke during the study or siblings interrupted), and due to infant crying and not completing the study. Thus, after exclusion, the final data sample we analyzed is 90 infants.

5. Baseline Characteristics

The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.

6. Primary Endpoint

The registry lists the primary outcome as Participants' Average Time Spent Looking at Stimuli According to Condition, measured over After the infants completed the study (which lasted about 10 minutes), two coders viewed the video recording of the session to measure infants' looking at the affiliation and disengagement stimuli..

The listed primary endpoint is participants’ average time spent looking at stimuli according to condition. The unit is seconds, and the summary measure is a mean with standard deviation. The measurement concerns infants’ looking at affiliation and disengagement stimuli after they completed the study.

According to the registry record, two coders who were blind to assigned condition viewed each session video and measured looking time. They compared their values; when they disagreed, they discussed the difference and selected one value. Thus, the record describes a single value for each outcome measurement, either shared by the coders or agreed upon after discussion. It does not describe averaging the coders’ initial measurements or report a numerical measure of coder agreement.

Looking time is used in this study as an observed behavioral measure related to infants’ attention to the stimuli. In general, an endpoint needs a clear definition and a consistent measurement procedure so that group summaries have an interpretable meaning. The coder-blinding and reconciliation process described in the record address aspects of measurement, but do not by themselves establish the meaning of a difference in looking time.

The record does not give condition-specific means, standard deviations, confidence intervals, or a test result for this endpoint. It also says the primary outcome has several categories or time points and was not reduced to one comparison. Consequently, the endpoint description does not establish which specific contrast or time point should be treated as the decisive test of the study question.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does a mean summarize?

For a continuous measure such as looking time in seconds, the mean gives a group-level summary of observed values. It can be useful for comparing typical levels across conditions, but it does not show the full distribution. Individual infants can vary, and the same mean can arise from different patterns of observations. The registry identifies the mean as the summary measure and the standard deviation as its measure of dispersion, but does not report the numerical values by condition.

A standard deviation describes spread among observations around the mean. It is not the same as the uncertainty in the estimated mean. Precision of an estimate depends on both variability and how many observations contribute to it. The registry record does not give the number of infants contributing usable endpoint data in each condition, so precision cannot be reconstructed from the information recorded. This explanation is general; no additional trial-specific calculation follows from it.

What would a comparison estimate?

A comparison between conditions would ordinarily express how the outcome differs between the groups under a defined analysis. Interpretation depends on identifying the outcome category, time point, and contrast. The registry says the primary outcome has several categories or time points and was not reduced to one comparison. It does not state a particular primary contrast or provide estimates for the possible comparisons. Without those details, readers cannot tell which difference is the primary inferential target or whether any reported analysis would address it.

General statistical interpretation distinguishes the estimated size of a contrast from the uncertainty around it. A confidence interval describes a range of values compatible with the data and a specified statistical procedure. A narrow interval indicates greater precision than a broad interval, but precision is not the same as importance. No confidence interval or contrast estimate for the primary outcome is reported in the registry record, so these interpretations cannot be applied to a specific result.

Why does blinding matter for measurement?

The registry says that two coders measuring looking time were blind to the assigned condition. In general, blinding can reduce the chance that expectations about condition influence judgment when coding behavior from video. The described process also compares coder values and uses discussion to resolve disagreement. These are relevant procedural details, but the registry does not report initial coder values, a measure of agreement, or the frequency of disagreements. The final reconciled measure therefore cannot be evaluated for reliability from the record alone.

Measurement procedures matter because group comparisons can be affected by errors in how an endpoint is recorded. A consistent procedure can limit some sources of variation, while inconsistent or subjective decisions can introduce others. Coder blinding does not eliminate every potential measurement issue, and agreement after discussion does not quantify how reproducible the initial ratings were. These are general considerations, not claims that a particular measurement problem occurred in this study.

What does randomization contribute?

In general, random allocation is intended to make assigned conditions comparable with respect to measured and unmeasured characteristics, apart from chance variation. It supports causal interpretation when the design is implemented appropriately and when outcome analysis follows the assignment structure. The registry labels allocation as randomized, but does not report sequence generation, concealment, adherence to assigned condition, or an analysis that preserves the randomization. The label alone cannot answer those implementation questions.

A parallel design generally compares outcomes among participants assigned to separate conditions. This is distinct from a design in which each participant experiences multiple conditions. The registry lists a parallel model and describes racial pairings of adults across conditions. It does not report a detailed statistical model or explain how any participant-level or stimulus-level dependence was handled. If observations are clustered or repeated, a method that ignores that structure can misstate uncertainty; whether such a structure applied to the analysis is not established in the record.

What can a planning illustration tell readers?

In general, sample-size planning asks how many participants per arm would be needed to detect a specified effect under stated assumptions. Such an illustration is a planning calculation, not an observed result and not a measure of the probability that a completed study found a true effect. The registry describes assumptions for an illustration based on the observed effect: a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and an effect defined as a stated fraction of the observed effect. The record also notes that event totals apply to time-to-event illustrations, whereas other illustrations concern participants per arm.

Those assumptions do not establish the study’s original design plan. The record does not report the trial’s own sample-size justification, and the primary outcome was not reduced to one comparison for the analysis described by the skip note. A planning calculation based on an observed effect is especially dependent on that effect estimate, which is not reported numerically in the registry record. It should not be interpreted as observed power or as proof that the study was adequately or inadequately sized.

Why are analysis details necessary?

A statistical result depends on more than an endpoint label. It depends on which observations enter the analysis, how missing measurements are treated, which comparisons are made, and what model or test is used. The registry record does not report these details sufficiently for an independent reconstruction. In general, a prespecified analysis can clarify which result answers the primary question and how uncertainty is quantified. The record does not report a statistical analysis plan, so the intended methods and any deviations from them cannot be assessed.

10. Multiplicity, Missing Data and Analysis Populations

The registry identifies the primary outcome as having several categories or time points and notes that it was not reduced to one comparison. This matters because testing multiple outcomes, categories, time points, or contrasts can increase the chance of at least one apparently unusual result when each is assessed separately. General approaches to multiplicity include defining a primary contrast in advance, adjusting inference across a family of tests, or treating analyses as exploratory. The registry record does not report which approach, if any, was used.

The record reports enrollment of 128 and says that 38 infants were excluded. It gives examples involving technical issues, such as missing or cut-off video, and parental or family interference, such as speaking during the study or interruption by siblings. The description of the exclusion reasons is incomplete. The record does not report the number excluded for each reason, the number with usable endpoint data in each condition, or whether exclusions occurred before or after condition assignment.

Missing-data handling is not reported in the registry record. It is therefore unclear whether the outcome analysis used only complete measurements, applied an imputation method, or handled unavailable observations in another way. In general, excluding participants with missing outcomes can affect a comparison if the reasons for missingness are related to condition or looking behavior. This is a methodological possibility, not a finding about the study.

The analysis population is also not described sufficiently to determine whether the analysis followed randomized assignment, included only infants who completed the procedure, or used another eligibility rule. The record does not report an intention-to-treat analysis or a per-protocol analysis. It also does not provide a participant flow by condition. These omissions limit assessment of how the reported enrollment and exclusions relate to the primary analysis.

11. What the Result Does, and Does Not, Mean

The study addresses a question about infants’ expectations of social relationships and whether racial pairing serves as a cue for predicting those relationships. Its registered behavioral measure is looking time to affiliation and disengagement stimuli. The registry record provides procedural information about how that measure was coded, but does not report numerical outcome summaries or an inferential result for the primary question.

Accordingly, the record does not support a conclusion that infants did or did not use race as a cue in this study. It does not quantify an observed difference between White-White, Black-Black, and Black-White conditions, nor does it show how uncertain any such difference would be. Absence of numerical results in the registry record should not be mistaken for a finding of no difference or for evidence of equivalence.

Even when looking-time differences are measured, their statistical meaning and their conceptual meaning are distinct. A statistical contrast would describe a pattern in the recorded behavior under a particular analysis. Interpreting that pattern as evidence about social expectations requires a justified connection between the behavioral measure and the underlying construct. The record describes the study’s intended question, but does not report validation evidence or numerical results that would allow that interpretive step to be evaluated.

The registry entries of zero for listed adverse-event categories are limited to the recorded categories and counts. They do not establish that all possible events were assessed or that the study has implications for clinical safety. The study is described as basic science, and its listed endpoint is behavioral rather than a clinical health outcome.

The most defensible reading is therefore about what the record documents: a randomized parallel procedure, a coder-based looking-time measure, and exclusions with partly described reasons. The outcome evidence required to judge the primary research question is not reported in the registry record. Broader claims about infants, social perception, or real-world behavior would require evidence beyond the record’s design description.

12. Why This Trial Matters Statistically

This study is statistically interesting because its central question concerns an unobserved concept, infants’ expectations about social relationships, while its endpoint is an observed behavior: time spent looking at stimuli. Statistical analysis can summarize and compare that behavior, but the interpretation depends on how closely the measure represents the underlying concept. A clear measure and a transparent analysis are therefore essential to connect observed looking time with the research question.

The design also makes the choice of comparison important. The listed conditions vary in the racial pairing of the adults, while the outcome description refers to affiliation and disengagement stimuli and the record notes several categories or time points. An interpretable analysis needs to specify which condition contrast and which outcome component answer the primary question. The registry record does not report a single comparison or the numerical estimates, so readers cannot evaluate that connection from the recorded results.

Measurement by coders who are blind to assigned condition is a relevant safeguard in behavioral research. The discussion-based resolution of coder disagreements is also part of the measurement process. Statistical transparency would be strengthened by reporting how much the coders initially agreed and how the final values entered the analysis; those details are not reported in the registry record.

Finally, the exclusions illustrate why participant flow and missing outcome handling matter. Technical problems and family interference can affect whether a video yields a usable measure. Without condition-specific analysis counts and a stated missing-data approach, it is difficult to determine how the available observations relate to the randomized design. These considerations are general lessons in interpreting behavioral trials, not evidence that bias occurred in this study.

13. Limitations

• The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
• Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.

The registry record does not report the condition-specific means or standard deviations for the primary outcome, nor a contrast estimate, confidence interval, p-value, or other inferential result. As a result, the size, direction, and precision of the primary-outcome pattern cannot be evaluated from the record. The stated research question cannot be answered from the design and endpoint descriptions alone.

The endpoint description refers to affiliation and disengagement stimuli, while the registry notes that the primary outcome includes several categories or time points and was not reduced to one comparison. The record does not clarify the exact structure of those categories or identify a single primary contrast. This makes it difficult to determine which analysis would constitute the primary test and how multiplicity was addressed.

The exclusion account is incomplete. It reports that 38 infants were excluded from the 128 recruited and lists technical and family-interference examples, but the text ends before all reasons are specified. Counts by reason, condition, and analysis eligibility are not reported. The record also does not say how missing endpoint measurements were handled or define the analysis population.

Although two coders were blind to condition and reconciled disagreements through discussion, the record does not report their initial agreement or any reliability statistic. It does not give details sufficient to evaluate allocation concealment, the implementation of masking, or the statistical model. The completed-study status does not resolve these reporting gaps.

These limitations concern what can be evaluated from the registry record. They do not establish that the study procedures were inadequate or that a particular source of bias occurred. They do restrict independent assessment of the outcome evidence and its relation to the stated research question.

14. Related Tutorials

15. Related Statistical Calculators

16. Sources

• ClinicalTrials.gov: Babies' Expectations About Racial Interactions — NCT05324007.
• Registry record last updated 2024-04-24; status last verified 2024-04.
• Results first posted 2024-04-24.
• Data retrieved from ClinicalTrials.gov on 2026-11-09.
• Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.

17. Record Summary

The registry record describes NCT05324007, titled Babies' Expectations About Racial Interactions, as a completed randomized, quadruple-masked, parallel basic-science study sponsored by the University of Chicago. It lists infants and the White-White, Black-Black, and Black-White conditions. The study’s stated purpose is to examine whether infants view race as a useful cue for predicting third-party social relationships.

The primary measure is average looking time to affiliation and disengagement stimuli, recorded in seconds and summarized as a mean with standard deviation. Two coders blind to assigned condition measured video recordings and discussed disagreements to select a final value. The record reports enrollment of 128 and exclusions of 38 infants, with some but not all exclusion reasons described.

Numerical primary-outcome results, a defined primary contrast, missing-data methods, and a detailed statistical analysis plan are not reported in the registry record. The record therefore documents the research design and measurement process but does not permit an assessment of the size or precision of the outcome differences.