Investigating Gender Differences under Time Pressure in Financial Risk Taking.

There is a significant gender imbalance on financial trading floors. This motivated us to investigate gender differences in financial risk taking under pressure. We used a well-established approach from behavior economics to analyze a series of risky monetary choices by male and female participants with and without time pressure. We also used second to fourth digit ratio (2D:4D) and face width-to-height ratio (fWHR) as correlates of pre-natal exposure to testosterone. We constructed a structural model and estimated the participants' risk attitudes and probability perceptions via maximum likelihood estimation under both expected utility (EU) and rank-dependent utility (RDU) models. In line with existing research, we found that male participants are less risk averse and that the gender gap in risk attitudes increases under moderate time pressure. We found that female participants with lower 2D:4D ratios and higher fWHR are less risk averse in RDU estimates. Males with lower 2D:4D ratios were less risk averse in EU estimations, but more risk averse using RDU estimates. We also observe that men whose ratios indicate a greater prenatal exposure to testosterone exhibit a greater optimism and overestimation of small probabilities of success.

Interoceptive Ability Predicts Survival on a London Trading Floor.

Interoception is the sensing of physiological signals originating inside the body, such as hunger, pain and heart rate. People with greater sensitivity to interoceptive signals, as measured by, for example, tests of heart beat detection, perform better in laboratory studies of risky decision-making. However, there has been little field work to determine if interoceptive sensitivity contributes to success in real-world, high-stakes risk taking. Here, we report on a study in which we quantified heartbeat detection skills in a group of financial traders working on a London trading floor. We found that traders are better able to perceive their own heartbeats than matched controls from the non-trading population. Moreover, the interoceptive ability of traders predicted their relative profitability, and strikingly, how long they survived in the financial markets. Our results suggest that signals from the body - the gut feelings of financial lore - contribute to success in the markets.

Cortisol shifts financial risk preferences.

Risk taking is central to human activity. Consequently, it lies at the focal point of behavioral sciences such as neuroscience, economics, and finance. Many influential models from these sciences assume that financial risk preferences form a stable trait. Is this assumption justified and, if not, what causes the appetite for risk to fluctuate? We have previously found that traders experience a sustained increase in the stress hormone cortisol when the amount of uncertainty, in the form of market volatility, increases. Here we ask whether these elevated cortisol levels shift risk preferences. Using a double-blind, placebo-controlled, cross-over protocol we raised cortisol levels in volunteers over 8 d to the same extent previously observed in traders. We then tested for the utility and probability weighting functions underlying their risk taking and found that participants became more risk-averse. We also observed that the weighting of probabilities became more distorted among men relative to women. These results suggest that risk preferences are highly dynamic. Specifically, the stress response calibrates risk taking to our circumstances, reducing it in times of prolonged uncertainty, such as a financial crisis. Physiology-induced shifts in risk preferences may thus be an underappreciated cause of market instability.

Repair of traumatic muscle herniation with acellular porcine collagen matrix.

BACKGROUND: Muscle hernias are uncommon clinical conditions with no uniform solution of repair. Biocompatible mesh allows for repair of hernias without the donor site morbidity and complications from direct repair under tension. METHODS: Over a 6-month period at a Level 1 Trauma centre, four consecutive symptomatic muscle hernias were identified, two in the forearm and two in the lower limb. Three resulted from high-speed motorbike accidents, one from a mining accident. All patients had hernia repair at a minimum of 4 months post accident. A 10 × 15 cm × 1.0 mm sheet of acellular collagen matrix was fashioned to fit as an underlay of the fascia defect. Patients were clinically followed at the 2-, 6-, 12- and 26-week mark. Final phone contact was made 18 months post-operatively. RESULTS: All patients were pleased with their cosmetic and functional outcomes. All patients returned to work and sport 3 months after reconstruction. CONCLUSION: Symptomatic hernias as a result of trauma can be safely reconstructed with a biological mesh implant. This approach can prevent complications from previously described methods and return to active lifestyles with good results.

Changes in hip fracture incidence, mortality and length of stay over the last decade in an Australian major trauma centre.

PURPOSE: The aim of this study was to describe the population-based longitudinal trends in incidence, 30-day mortality and length of stay of hip fracture patients in a tertiary referral trauma centre in Newcastle, New South Wales, Australia, and identify the factors associated with increased 30-day mortality. METHODS: A retrospective database and chart review was conducted to patients aged ≥65 years with a diagnosis of femoral neck or pertrochanteric fracture admitted to the John Hunter Hospital between 01 January 2002 and 30 December 2011. The main outcome measure was 30-day mortality; secondary outcome was acute length of stay. RESULTS: There were 4,269 eligible patients (427±20 per year) with hip fractures over the 10-year study period. The absolute incidence increased slightly (p=0.1) but the age-adjusted rate decreased (p≤0.0001). The average age (83.5±7.1 years) and percentage of females (73.7%) did not change. Length of stay increased by a factor of 2.5% per year (p<0.0001). Thirty-day mortality decreased from 12.3% in 2002 to 8.20% in 2011 (p=0.0008). Independent risk factors associated with increased 30-day mortality were longer admissions (p<0.0001), increased age (p=0.005), dementia (p=0.01), male gender (p<0.0001), higher American Society of Anaesthesiologists score (p<0.0001), and longer time to operating theatre (p=0.002). CONCLUSIONS: Despite the relative ageing of our population, a decrease in the age-standardised rate of fractured hip in elderly patients has seen the number of admissions remain unchanged in our institution from 2002 to 2011. There was a decrease in 30-day mortality, while length of stay increased.