Ambiguous Locations Research Articles

Effect of pre-session discrimination training on performance in a judgement bias test in dogs

Spatial judgement bias tests (JBTs) can involve teaching animals that a bowl provides a reward in one location but does not in another. The animal is then presented with the bowl placed between the rewarded and the unrewarded locations (i.e., ambiguous locations) and their latency to approach reflects expectation of reward or ‘optimism’. Some suggest that greater ‘optimism’ indicates better welfare. Performance in JBTs, however, may also indicate a learning history independently from welfare determinants. We hypothesized that dogs’ ‘optimism’ in a follow-up JBT may be impacted by a learning treatment involving additional trials of a different discrimination task. Once enrolled, companion dogs (n = 16) were required to complete three study phases: (1) a pre-treatment JBT, (2) a learning treatment, and (3) a post-treatment JBT. During the JBTs, dogs were presented with five locations: one rewarded, one unrewarded, and three ambiguous (all unrewarded). Dogs were randomly assigned to a trial-based learning task—a nose-touch to the palm of the hand. In the Experimental discrimination treatment phase (n = 8), dogs were presented with two hands in each trial and only rewarded for touching one specific hand. In the Control treatment phase (n = 8), dogs were presented with one hand per trial in alternating sequence and were yoked to dogs in the Experimental group to receive the same number of rewarded and unrewarded trials (to control for possible frustration). Using a repeated measures mixed model with JBT repeated within dog, we found no difference in the change in approach latency to the ambiguous locations between the dogs across treatments. ‘Optimism’ as measured in this JBT was not altered by the additional discrimination trials used in our study.

The odour of an unfamiliar stressed or relaxed person affects dogs’ responses to a cognitive bias test

Dogs can discriminate stressed from non-stressed human odour samples, but the effect on their cognition is unstudied. Using a cognitive bias task, we tested how human odours affect dogs’ likelihood of approaching a food bowl placed at three ambiguous locations (“near-positive”, “middle” and “near-negative”) between trained “positive” (rewarded) and “negative” (unrewarded) locations. Using odour samples collected from three unfamiliar volunteers during stressful and relaxing activities, we tested eighteen dogs under three conditions: no odour, stress odour and relaxed odour, with the order of test odours counterbalanced across dogs. When exposed to stress odour during session three, dogs were significantly less likely to approach a bowl placed at one of the three ambiguous locations (near-negative) compared to no odour, indicating possible risk-reduction behaviours in response to the smell of human stress. Dogs’ learning of trained positive and negative locations improved with repeated testing and was significant between sessions two and three only when exposed to stress odour during session three, suggesting odour influenced learning. This is the first study to show that without visual or auditory cues, olfactory cues of human stress may affect dogs’ cognition and learning, which, if true, could have important consequences for dog welfare and working performance.

Direct acoustic velocity vector measurements for evaluation of multichannel sound reproduction systems with signals of varied partial coherence

In multichannel sound reproduction systems, the perceived virtual auditory scene is strongly influenced by inter-channel phase-shifts and the degree of mutual coherence among channel signals. Such degrees of freedom may be employed to effect an expanded virtual sound stage or a sense of spaciousness, but they also may lead to unwanted spectral coloration, diffuse or ambiguous virtual source locations, or startling and disorienting spatial image perceptions often described as “phaseyness.” Such effects may be described and understood in terms of the acoustic velocity in the vicinity of the listener. In this work we present theoretical predictions of the acoustic velocity vector for a stereo reproduction system with channel signals of varying phase and levels of mutual coherence, and we report direct measurements of the acoustic velocity vector employing a 3D sound intensity probe for several specific cases. Acoustic velocity vector predictions and measurements also are correlated with listener perceptions. The presented measurements are also compared to subjective localization of sound sources. The direct measurement of the acoustic velocity vector in spatial sound reproduction systems is a useful tool to quantitatively evaluate the performance of multi-channel spatial audio reproduction systems, to predict listener perceptions of the acoustic field reproduced by such systems, and to investigate the impact of early reflections in a room on localization.

Fuzzy Semantics for Arbitrary-Shaped Scene Text Detection.

To robustly detect arbitrary-shaped scene texts, bottom-up methods are widely explored for their flexibility. Due to the highly homogeneous texture and cluttered distribution of scene texts, it is nontrivial for segmentation-based methods to discover the separatrixes between adjacent instances. To effectively separate nearby texts, many methods adopt the seed expansion strategy that segments shrunken text regions as seed areas, and then iteratively expands the seed areas into intact text regions. In seek of a more straightforward way that does not rely on seed area segmentation and avoid possible error accumulation brought by iterative processing, we propose a redundancy removal strategy. In this work, we directly explore two types of fuzzy semantics-text and separatrix-that do not possess specific boundaries, and separate cluttered instances by excluding the separatrix pixels from text regions. To deal with the fuzzy semantic boundaries, we also conduct reliability analysis in both optimization and inference stage to suppress false positive pixels at ambiguous locations. Experiments on benchmark datasets demonstrate the effectiveness of our method.

The effect of repeated testing on judgement bias in domestic dogs (Canis familiaris)

Judgement bias paradigms are increasingly being used as a measure of affective state in dogs. Approach to an ambiguous stimulus is commonly used as a measure of affect, however, this may also be influenced by learning. This study directly measured the impact of learning on a commonly used judgement bias paradigm in the absence of an affective state manipulation. Dogs (N = 15) were tested on a judgement bias task across five sessions. The dogs’ latency to approach a bowl placed in one of three ambiguous locations between non-baited (negative) and baited (positive) locations was measured. Results show that session number had a significant effect on the dogs’ latencies to reach the ambiguous bowl locations, with post-hoc tests revealing that dogs were significantly slower to approach the locations as the number of sessions increased. Session number also had a significant effect on the number of times the dogs did not approach the bowl within 30 s of being released, with the number of no approaches generally increasing across sessions. When dog identity was included as a fixed effect, a significant effect on latency to approach was found, suggesting that some dogs were consistently faster than others across sessions. To assess whether the paradigm produced repeatable results, Intraclass Correlation Coefficients were used. A low degree of reliability was found between latencies to approach each bowl position across sessions. This study demonstrates that dogs learned that the ambiguous locations were not rewarded with repeated exposures, and that this impacted their responses. We conclude that this judgement bias paradigm may require further consideration if applied across multiple exposures and that repeated results should be interpreted with caution as they are likely impacted by learning.

Judgment Bias During Gestation in Domestic Pigs.

In humans and rats, changes in affect are known to occur during pregnancy, however it is unknown how gestation may influence mood in other non-human mammals. This study assessed changes in pigs' judgment bias as a measure of affective state throughout gestation. Pigs were trained to complete a spatial judgment bias task with reference to positive and negative locations. We tested gilts before mating, and during early and late gestation, by assessing their responses to ambiguous probe locations. Pigs responded increasingly negatively to ambiguous probes as gestation progressed and there were consistent inter-individual differences in baseline optimism. This suggests that the pigs' affective state may be altered during gestation, although as a non-pregnant control group was not tested, an effect of learning cannot be ruled out. These results suggest that judgment bias is altered during gestation in domestic pigs, consequently raising novel welfare considerations for captive multiparous species.

The Acute Pharmacological Manipulation of Dopamine Receptors Modulates Judgment Bias in Japanese Quail.

We have studied the effects of dopamine antagonists and agonists on Japanese quail behavior in the spatial judgment task. Twenty-four Japanese quail hens were trained in the spatial discrimination task to approach the feeder placed in the rewarded location (Go response, feeder containing mealworms) and to not approach the punished location (No-Go response, empty feeder plus aversive sound). In a subsequent spatial judgment task, the proportion of Go responses as well as approach latencies to rewarded, punished, and three ambiguous locations (near-positive, middle, near-negative, all neither rewarded nor punished) were assessed in 20 quail hens that successfully mastered the discrimination task. In Experiment 1, each bird received five treatments (0.1 and 1.0 mg/kg of dopamine D1 receptor antagonist SCH 23390, 0.05 and 0.5 mg/kg of dopamine D2 receptor antagonist haloperidol, and saline control) in a different order, according to a Latin square design. All drugs were administered intramuscularly 15 min before the spatial judgment test, with 2 days break between the treatments. Both antagonists caused a significant dose-dependent increase in the approach latencies as well as a decrease in the proportion of Go responses. In Experiment 2, with the design analogous to Experiment 1, the hens received again five treatments (1.0 and 10.0 mg/kg of dopamine D1 receptor agonist SKF 38393, 1.0 and 10.0 mg/kg of dopamine D2 receptor agonist bromocriptine, and saline control), applied intramuscularly 2 h before the test. The agonists did not have any significant effect on approach latencies and the proportion of Go responses in the spatial judgment task, as compared to the saline control, except for 10.0 mg/kg SKF 38393, which caused a decrease in the proportion of Go responses. The approach latency and the proportion of Go responses were affected by the cue location in both experiments. Our data suggest that the dopamine D1 and D2 receptor blockade leads to a decrease in the reward expectation and the negative judgment of stimuli. The effect of dopamine receptor activation is less clear. The results reveal that dopamine receptor manipulation alters the evaluation of the reward and punishment in the spatial judgment task.

Isling: A Tool for Detecting Integration of Wild-Type Viruses and Clinical Vectors

Detecting viral and vector integration events is a key step when investigating interactions between viral and host genomes. This is relevant in several fields, including virology, cancer research and gene therapy. For example, investigating integrations of wild-type viruses such as human papillomavirus and hepatitis B virus has proven to be crucial for understanding the role of these integrations in cancer. Furthermore, identifying the extent of vector integration is vital for determining the potential for genotoxicity in gene therapies. To address these questions, we developed isling, the first tool specifically designed for identifying viral integrations in both wild-type and vector from next-generation sequencing data. Isling addresses complexities in integration behaviour including integration of fragmented genomes and integration junctions with ambiguous locations in a host or vector genome, and can also flag possible vector recombinations. We show that isling is up to 1.6-fold faster and up to 170% more accurate than other viral integration tools, and performs well on both simulated and real datasets. Isling is therefore an efficient and application-agnostic tool that will enable a broad range of investigations into viral and vector integration. These include comparisons between integrations of wild-type viruses and gene therapy vectors, as well as assessing the genotoxicity of vectors and understanding the role of viruses in cancer.

Dogs are more pessimistic if their owners use two or more aversive training methods

Domestic dogs are trained using a range of different methods, broadly categorised as reward based (positive reinforcement/negative punishment) and aversive based (positive punishment/negative reinforcement). Previous research has suggested associations between use of positive punishment-based techniques and undesired behaviours, but there is little research investigating the relative welfare consequences of these different approaches. This study used a judgement bias task to compare the underlying mood state of dogs whose owners reported using two or more positive punishment/negative reinforcement based techniques, with those trained using only positive reinforcement/negative punishment in a matched pair study design. Dogs were trained to discriminate between rewarded and unrewarded locations equidistant from a start box, and mean latencies recorded. Their subsequent latency to intermediate ‘ambiguous’ locations was recorded as an indication of whether these were perceived as likely to contain food or not. Dogs trained using aversive methods were slower to all ambiguous locations. This difference was significant for latency to the middle (Wilcoxon Z = − 2.380, P = 0.017), and near positive (Wilcoxon Z = − 2.447, P = 0.014) locations, suggesting that dogs trained using coercive methods may have a more negative mood state, and hence that there are welfare implications of training dogs using such methods.

Using judgment bias test in pet and shelter dogs (Canis familiaris): Methodological and statistical caveats.

It is now widely agreed that a positive affective state is a crucial component of animal well-being. The judgment bias test represents a widespread tool used to assess animals’ optimistic/pessimistic attitude and to evaluate their emotional state and welfare. Judgment bias tests have been used several times with dogs (Canis familiaris), in most cases using a spatial test with a bowl placed in ambiguous positions located between a relatively positive trained location (P) which contains a baited bowl and a relatively negative trained location (N) which contains an empty bowl. The latency to approach the bowl in the ambiguous locations is an indicator of the dog’s expectation of a positive/negative outcome. However, results from such tests are often inconclusive. For the present study, the judgment bias test performance of 51 shelter dogs and 40 pet dogs was thoroughly analysed. A pattern emerged with shelter dogs behaving in a more pessimistic-like way than pet dogs. However, this difference between the two populations was detected only when analysing the raw latencies to reach the locations and not the more commonly applied adjusted score (i.e. average latency values). Furthermore, several methodological caveats were found. First of all, a non-negligible percentage of dogs did not pass the training phase, possibly due to the experimental paradigm not being fully suited for this species. Second, results showed a high intra-dog variability in response to the trained locations, i.e. the dogs’ responses were not consistent throughout the test, suggesting that animals may not have fully learned the association between locations and their outcomes. Third, dogs did not always behave differently towards adjacent locations, raising doubts about the animals’ ability to discriminate between locations. Finally, a potential influence of the researcher’s presence on dogs’ performance emerged from analyses. The implications of these findings and potential solutions are discussed.

The Use of a “Go/Go” Cognitive Bias Task and Response to a Novel Object to Assess the Effect of Housing Enrichment in Sheep (Ovis aries)

ABSTRACT It is widely acknowledged that environmental enrichment can improve animals’ welfare and emotional state. This study used cognitive bias and response to a novel object to assess the effect of enriched housing on emotional state in sheep. Eighteen sheep were trained to discriminate between high-quality and low-quality reward locations using a go/go task. Sheep were allocated to a housing treatment (enriched or standard) for three weeks. Judgment bias tests were conducted using three ambiguous, unrewarded locations across three days, followed by assessing responses to a novel object. Effects of anxiety levels shown in training on responses to ambiguous locations and to the presence of a novel object were assessed. Enriched-housed sheep tended to have shorter latencies to approach ambiguous positions than standard-housed sheep (P = 0.08), particularly to the near and middle locations. Sheep from standard housing tended to have shorter latencies to approach food with the novel object present than sheep from enriched hosing (P = 0.06). This study shows that enrichment can affect emotional state and that go/go tasks can be successful in sheep and should be considered in future studies of emotional state.

How Accurate are Locations in Malaysian Accident Data? Development of a Rectification Procedure based on Nested Filtered Search Technique

Errors in the accident data arise due to several individual and institutional shortcomings with inaccurate or ambiguous locations being the most serious amongst them. To overcome this issue a procedure has been devised in this study to rectify accident locations in the Malaysian accident data. The algorithm uses filtered search technique to match the accidents from the accident database with intersections from the field database. A total of 2809 accident records were screened for this purpose and 304 intersections were surveyed. The results showed that the algorithm is able to match up to 60% of the accidents to their respective locations depending upon the quality of the available records. Information related to only five parameters; major road width, landuse, lane marking, traffic control and geometry, are required for its implementation. Unlike geographic coordinates, these parameters are easily measurable and do not require any specialized equipment. The procedure is more relevant to low- and middle-income countries, where landmarks are much commonly used for location identification instead of geographic coordinates.

Pharmacologically-induced stress has minimal impact on judgement and attention biases in sheep

The emotional impact of exposure to stressors has not been well quantified in animals. We hypothesised that exogenous induction of stress in sheep would induce a pessimistic judgement bias and increased attention towards a threatening stimulus, suggestive of a negative emotional state. Stress was induced pharmacologically by administering synthetic adrenocorticotropic hormone. Judgement bias was assessed using a spatial go/no-go task after exposure to acute stress (one injection), chronic stress (21 daily injections) and acute-on-chronic stress (2 min isolation after 28 daily injections). Attention bias was assessed during chronic stress only (22 daily injections). In contrast with our hypotheses, there was no strong evidence that Synacthen administration altered judgement bias or attention bias at any stage of the experiment. Stressed sheep were more likely to approach ambiguous locations than saline Control animals, however, statistical evidence for models fitting treatment group was very weak. Overall, our findings suggest that elevated levels of cortisol may not fully explain changes to judgement bias observed in previous studies after environmentally-induced stress. Further studies are required to better understand which aspects of environmentally-induced stress alter judgement bias and to further validate cognitive methods of assessing affect in sheep.

Enrichment centered on human interaction moderates fear-induced aggression and increases positive expectancy in fearful shelter dogs

Some otherwise non-aggressive dogs may display fear-induced aggression under stressful conditions. Admittance to an animal shelter is a stressful experience for dogs, and aggression is often used as a criterion by shelters for precluding opportunities for adoption. We, therefore, examined whether a program of enrichment centered around a form of human interaction known to reduce the stress of shelter dogs would also reduce the aggression of fearful dogs and improve their general welfare. Fearful dogs displaying signs of aggression, as well as dogs displaying neither fear nor aggression, either did or did not receive 30 min a day of human interaction in a secluded room for approximately the first 5 days in a shelter. We then determined the number of enriched and non-enriched fearful and non-fearful dogs that passed a standard test of dog aggression as typically implemented in this shelter to determine eligibility for adoption. We also examined the affective state of dogs in a test of cognitive bias. In two separate experiments, we found that most fearful dogs without enrichment failed the aggression test, whereas most fearful dogs undergoing enrichment completed this assessment successfully (P < 0.001 in each experiment). In contrast, nearly all non-fearful dogs passed the aggression test regardless of enrichment experience. In cognitive bias testing, enrichment reduced the latency at which fearful dogs approached two locations at which the likelihood of reinforcement was ambiguous, a measure of increased positive expectancy (P”s < 0.01). Unexpectedly non-fearful dogs receiving enrichment approached one of the ambiguous locations more slowly than non-enriched controls (P < 0.05), a finding that might be an artifact of the testing procedures used here. While the generality of the results needs to be tested in other populations and shelter environments, the findings: 1) document the vulnerability of dogs exhibiting fear-induced aggression in a shelter environment; 2) demonstrate the ability of an enrichment program focusing on human interaction to reduce aggressiveness in these dogs and thereby increase their chances of being offered for adoption; and, 3) indicate a more-general outcome of the enrichment procedure on the affective state of fearful dogs.

Does the cognitive bias test in dogs depend on spatial learning?

Cognitive bias tests have been used to measure affective states in dogs. The results may also involve spatial learning and memory when location is used as the cue. In this study, we evaluated the performance of 16 Labrador retriever dogs with a cognitive bias test that used spatial location as the cue and compared the results to the dogs’ performance on a delayed nonmatching to position (DNMP) operant procedure. All dogs completed the cognitive bias test, whereas only 9 of 16 completed DNMP acquisition criteria within a maximum of 300 trials (mean ± SEM for successful dogs = 187.8 ± 19.2 trials). A negative correlation was observed between the number of trials required for DNMP acquisition and the mean latencies to the near positive (P = 0.001, r2 = 0.56, n = 16) and near negative (P = 0.013, r2 = 0.39, n = 16) ambiguous locations on the cognitive bias test. For the 9 dogs who met DNMP acquisition criteria within 300 trials, this correlation remained, with a significant negative correlation observed for the near positive (P = 0.01, r2 = 0.64) and near negative (P = 0.055, r2 = 0.43) ambiguous positions and the number of DNMP trials. The observed association between a classic test of spatial working memory (DNMP) and the cognitive bias test suggest that the cognitive bias test may also rely on spatial learning in some dogs. This finding suggests that the effect of spatial learning ability may need to be acknowledged in tests that use location as the discriminatory cue.

Colon Cancer Tumor Location Defined by Gene Expression May Disagree With Anatomic Tumor Location

BackgroundCancers of the right colon have been shown to differ from left-side colon cancers in prognosis, response to epithelial growth factor receptor inhibitors, microsatellite instability and BRAF mutation status, and other molecular characteristics. Clinical application of these differences will benefit from a deeper understanding of how tumor location defines and is defined by gene expression. Materials and MethodsThis study was carried out using Affymetrix microarray datasets (Cohort A: training set, n = 352; validation set, n = 519) and samples from The Cancer Genome Atlas Colon Adenocarcinoma database (Cohort B: n = 408), in which tumor location was reported. Gene expression patterns characteristic of tumor side were identified in a manner unbiased by statistical classification method. ResultsIn the Cohort A validation set, the anatomic locations of 75% of tumors agree with the locations predicted by gene expression (so-called genomic location), whereas 8% of tumors had genomic locations discordant with their anatomic locations, and 17% of tumors had ambiguous genomic locations. Genomic location was a better predictor of microsatellite instability, CpG island methylator phenotype status, and BRAF mutation status than anatomic location. Tumors with ambiguous genomic location were significantly (P = 1.3 × 10−7) more likely to have the mesenchymal consensus molecular subtype (40%) than those with a specific genomic location (18%). A genomic signature to predict genomic location was defined. ConclusionTumor location is increasingly considered in deciding treatment of a colon tumor. We showed that genomic location was superior to anatomic location as a predictor of molecular characteristics, suggesting that it may be a more accurate predictor of response.

Signature-oriented investigation of the efficacy of multicomponent drugs against heart failure.

Increasing attention has been paid to the application of precision medicine in heart failure (HF), and biomarker-based personalized medical care has shown great progress in HF management. Additionally, multicomponent drugs represented by traditional Chinese medicine (TCM) are demonstrating safety and efficacy in the management of HF. However, the potential mechanism is unclear, and the ambiguous clinical locations of TCM remain a hindrance to its extensive application. To meet this requirement, a precise investigation on the efficacy of multicomponent drugs against HF using the signature biomarkers-oriented approach was developed and applied to a conventional drug for cardiac disease, YiXinShu (YXS). On the basis of in vitro and in vivo efficacy evaluation of YXS against HF, and with the aid of proteomics and network pharmacology approaches, specific signatures regulated by YXS against HF were identified. YXS may show distinctive treatment features for those HF patients showing the elevation of fatty acid-binding protein 3 and cytoskeleton-associated protein 5, as well as other classic HF biomarkers. This study provides the first precise investigation of the efficacy of multicomponent drugs against HF and offers a practicable and low-cost approach for personalized management of HF.-Wei, J., Guo, F., Zhang, M., Xian, M., Wang, T., Gao, J., Wu, H., Song, L., Zhang, Y., Li, D., Yang, H., Huang, L. Signature-oriented investigation of the efficacy of multicomponent drugs against heart failure.

G-Tensor Directions in the Protein Structural Frame of Hyperthermophilic Archaeal Reduced Rieske-Type Ferredoxin Explored by 13C Pulsed Electron Paramagnetic Resonance.

Interpretation of magnetic resonance data in the context of structural and chemical biology requires prior knowledge of the g-tensor directions for paramagnetic metallo-cofactors with respect to the protein structural frame. Access to this information is often limited by the strict requirement of suitable protein crystals for single-crystal electron paramagnetic resonance (EPR) measurements or the reliance on protons (with ambiguous locations in crystal structures) near the paramagnetic metal site. Here we develop a novel pulsed EPR approach with selective 13Cβ-cysteine labeling of model [2Fe-2S] proteins to help bypass these problems. Analysis of the 13Cβ-cysteine hyperfine tensors reproduces the g-tensor of the Pseudomonas putida ISC-like [2Fe-2S] ferredoxin (FdxB). Its application to the hyperthermophilic archaeal Rieske-type [2Fe-2S] ferredoxin (ARF) from Sulfolobus solfataricus, for which the single-crystal EPR approach was not feasible, supports the best-fit g x-, g z-, and g y-tensor directions of the reduced cluster as nearly along Fe-Fe, S-S, and the cluster plane normal, respectively. These approximate principal directions of the reduced ARF g-tensor, explored by 13C pulsed EPR, are less skewed from the cluster molecular axes and are largely consistent with those previously determined by single-crystal EPR for the cytochrome bc1-associated, reduced Rieske [2Fe-2S] center. This suggests the approximate g-tensor directions are conserved across the phylogenetically and functionally divergent Rieske-type [2Fe-2S] proteins.

I say thee “neigh”: Rescued equids are optimistic in a judgment bias test

Abstract Changes in the affective state of neglected or abused animals can be difficult to quantify relative to physical improvements following rescue. Judgment bias as a measure of affective state was assessed in 8 horses and 2 donkeys that differed in their care history (abused/neglected or nonabused/non-neglected, hereafter described as rescued/nonrescued). On each training trial, a single bucket was presented at 1 of 2 locations; one that always contained food (reward) and another that never contained food (nonreward), and the latency to approach within 1 m of the bucket was recorded. Once differential responding to the 2 locations was established, buckets were presented at ambiguous locations (spatially intermediate between the reward and nonreward locations). Both groups approached the middle location with intermediate latencies. However, care history moderated the difference in latencies to respond to the reward versus the ambiguous locations. In fact, rescued equids approached the ambiguous locations more quickly than the nonrescued equids did, although there was no difference in approach to the reward stimulus. These results suggest that prior poor treatment at the hands of humans does not induce lasting pessimistic judgment biases, but further work is needed to examine changes in judgment bias following neglect or abuse.

What Majority-minority Society? A Critical Analysis of the Census Bureau’s Projections of America’s Demographic Future

On the basis of demographic projections by the U.S. Census Bureau, many Americans believe that their society will transition soon to a majority-minority one. The author analyzes the latest version of the projections and finds that the pivotal group is made up of individuals who come from mixed minority-white family backgrounds. It is projected to grow very rapidly in coming decades, and Census Bureau classification practices mean that most of its members are counted as minority. Without this classification, however, the emergence of a majority-minority society by 2060 is far from certain. Moreover, the evidence we possess about the characteristics, social affiliations, and identities of mixed individuals contradicts this Census Bureau practice, except for partly black individuals, who suffer from high levels of racism. Taking into account the ambiguous social locations of most mixed minority-white persons, the author suggests that, even should a majority-minority society appear, it will not look like we presently imagine it.