4. The g Beyond Factor Analysis

The problem of g, essentially , concerns two very fundamental questions: (1) Why are scores on various mental ability tests positively correlated? and (2) Why do people differ in performance on such tests? SOME DEFINITIONS To insure that we are talking the same language, we must review a few definitions. Clarity, explicitness, and avoidance of excess meaning or connotative overtones are virtues of a definition. Aside from these properties, a definition per se affords nothing to argue about. It has nothing to do with truth or reality; it is a formality needed for communication. A mental ability test consists of a number of items. An item is a task on which a person\u27s performance can be objectively scored, that is, classified (e.g., right or wrong, 1 or 0) , or graded on a scale (e.g., poor, fair, good, excellent, or 0, 1, 2,3), or counted (e.g., number of digits recalled, number of puzzle pieces fitted together within a time limit) , or measured on a ratio scale (e.g. , reaction time to a stimulus or the time interval between the presentation of a task and its completion). Objectively scored means that there is a high degree of agreement between observers or scorers or pointer readings in assigning a score to a person\u27s performance on an item. An item measures an ability if performance on the item can be objectively scored such that a higher score represents better performance in the sense of being more accurate, more correct, quicker, more efficient, or in closer conformance to some standard-regardless of any value judgment concerning the aesthetic, moral, social, or practical worth of the optimum performance on the particular task . An item measures a mental (or cognitive) ability if very little or none of the individual differences variance in task performance is associated with individual differences in physical capacity, such as sensory acuity or muscular strength, and if differences in item difficulty (percent passing) are uncorrelated with differences in physical capacities per se. In order for items to show individual differences in a given group of people, the items must vary in difficulty; that is, items without variance (0% or 100% passing) are obviously nonfunctional in a test intended to show individual differences. A test, like any scientific measurement, requires a standard procedure. This includes the condition that the requirements of the tasks composing the test must be understood by the testee through suitable instructions by the tester; and the fundaments of the task (i .e., the elements that it comprises) must already be familiar to the testee. Also, the testee must be motivated to perform the task. These conditions can usually be assured by the testee\u27s demonstrating satisfactory performance on easy exemplaries of the same item types as those in the test proper. Mental ability tests (henceforth called simply tests) that meet all these conditions can be made up in great variety, involving different sensory and response modalities, different media (e.g., words, numbers, symbols, pictures of familiar things, and objects), different types of task requirements (e.g ., discrimination, generalization, recall, naming, comparison, decision, inference), and a wide range of task complexity. The variety of possible items and even item types seems limited only by the ingenuity of the inventors of test items

A comparative study of some factor-analytic techniques

Ít appears then that if this study is to have any value it must aim at a rapprochement between psychologist and statistician. The psychological concepts which have inspired the development of factor analysis must be critically reviewed. Then the types of model most suited to represent these concepts at the concrete practical level must be chosen. The sampling theory necessary for a valid use of such models must then be stressed, and a statistical assessment of models in present use made.With the aim of fulfilling this programme a comparative approach has been chosen. But the number and variety of existing factorial techniques is so great that at the outset a choice of those which it was thought would lead to the most useful comparison and most pertinent discussion was necessary. Accordingly, the Centroid, or Simple Summation method, was chosen as being that most widely used. The Principal Component, or Principal Axes method was chosen as representing 'the statistician's choice'. Lastly, the Maximum Likelihood method was chosen as perhaps the only one so far to appear which meets the psychologist's acclaimed needs as well as the sterner dictates of sound statistical theory.All these are methods of extracting factors. They are considered in chapter III, where several correlation matrices have been factorized by two or more methods and the results presented for comparison. As well as the problem of factor extraction there is the equally important problem of deciding how many factors to extract. In the past this problem has been responsible for a great deal of controversy. Chapter IV is devoted to a discussion of it, and to an examination of some of the empirical rules which have been put forward for deciding when to stop factoring. Results given by these empirical rules are compared with those obtained by the use of efficient tests.To reiterate, comparisons of this kind are a feature of this study, for while it may be argued that in future with improved computing facilities research workers are likely to employ only efficient techniques in their basic research, it will be valuable to know just how efficient the older methods are. This will help when making comparisons with earlier studies and for making quick assessments of the possible value of analysing virgin data.In chapter V the vexed question of the interpretation of factors is considered. Here a number of the more recent suggestions for obtaining unique or objective solutions are employed, and the results they give are evaluated against the more orthodox precepts of common sense and experience. At this stage a plea is made for the more careful design of factorial experiments.In chapter VI the problem of factorial invariance and of the comparison of factors obtained from replicated experiments is dealt with. Empirical methods for comparing factors suggested by Barlow and Burt, and by Ahmavaara are reviewed and evaluated and an approach to the problem along more orthodox statistical lines is outlined and illustrated. The latter approach, however, does not prove fruitful from a practical viewpoint and an alternative approach - made possible by recent work by Bowe and by Lawley - is recommended.Finally, in chapter VII, the main conclusions reached in the thesis are summarised and the present status of factor analysis as a branch of statistical theory assessed. In conclusion it is recommended that the psychologist who has doubts about the value of factorial techniques should do a factorial study of his own. Only in this way will he have an opportunity of facing for himself the problems referred to, and of passing from theory to the immanence of a real experience

Multivariate complexity analysis of 3D surface form and function of centric diatoms at the Eocene–Oligocene transition

Complexity is important in the course of evolution, but consensus of what complexity analysis entails is elusive. In this study, multivariate complexity is measured and analyzed in terms of magnitude of change and the trends behind those changes. Multivariate morphological and functional complexities were analyzed using 3D surface models of centric diatom genera from the Eocene to Oligocene, a transitional time when temperatures cooled, sea levels rose, and glaciation increased. Diatoms were chosen for study because of their importance in biostratigraphy, biogeochemical cycling, productivity, food web dynamics, and sensitivity to environmental conditions. Probabilistic analysis using aMarkov chain indicated an increase in total complexity across the Eocene–Oligocene transition (EOT). Causal inference via structural equation modeling indicated weakly driven functional and morphological complexity trends over the EOT.Morphological and functional complexity trends differed with respect to predation resistance as responses to ecological complexity as environmental and climate change occurred across the EOT. Macroevolutionary patterns of morphological and functional complexity with respect to ecological complexity did not necessarily coincide over time.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/116860/1/2016JLP-MARMIC.pdfDescription of 2016JLP-MARMIC.pdf : main articl

Homo moralis: Personal characteristics, institutions, and moral decision-making

This paper studies how individual characteristics, institutions, and their interaction influence moral decisions. We validate a moral paradigm focusing on the willingness to accept harming third parties. Consequences of moral decisions are real. We explore how moral behavior varies with individual characteristics and how these characteristics interact with market institutions compared to situations of individual decision-making. Intelligence, female gender, and the existence of siblings positively influence moral decisions, in individual and in market environments. Yet in markets, most personalities tend to follow overall much lower moral standards. Only fluid intelligence specifically counteracts moral-eroding effects of markets

Patterns of genomic and phenomic diversity in wine and table grapes.

Grapes are one of the most economically and culturally important crops worldwide, and they have been bred for both winemaking and fresh consumption. Here we evaluate patterns of diversity across 33 phenotypes collected over a 17-year period from 580 table and wine grape accessions that belong to one of the world's largest grape gene banks, the grape germplasm collection of the United States Department of Agriculture. We find that phenological events throughout the growing season are correlated, and quantify the marked difference in size between table and wine grapes. By pairing publicly available historical phenotype data with genome-wide polymorphism data, we identify large effect loci controlling traits that have been targeted during domestication and breeding, including hermaphroditism, lighter skin pigmentation and muscat aroma. Breeding for larger berries in table grapes was traditionally concentrated in geographic regions where Islam predominates and alcohol was prohibited, whereas wine grapes retained the ancestral smaller size that is more desirable for winemaking in predominantly Christian regions. We uncover a novel locus with a suggestive association with berry size that harbors a signature of positive selection for larger berries. Our results suggest that religious rules concerning alcohol consumption have had a marked impact on patterns of phenomic and genomic diversity in grapes

Homo moralis: Personal characteristics, institutions, and moral decision-making

This paper studies how individual characteristics, institutions, and their interaction influence moral decisions. We validate a moral paradigm focusing on the willingness to accept harming third parties. Consequences of moral decisions are real. We explore how moral behavior varies with individual characteristics and how these characteristics interact with market institutions compared to situations of individual decision-making. Intelligence, female gender, and the existence of siblings positively influence moral decisions, in individual and in market environments. Yet in markets, most personalities tend to follow overall much lower moral standards. Only fluid intelligence specifically counteracts moraleroding effects of markets